Honda-SOHC

Dry powder is the most popular for home type use these days and is readily available. It is good for oil and fuel fires, electrical fires and general house fires. Downside is it makes a lot of mess and a lot of cleaning up. But like you say the alternative to not using it is a lot worse.  Dry powder extinguishes should be changed after a number of years as the powder can start to become packed down, particularly with vibration when the extinguisher is carried in a vehicle. 
Good all round general fire extinguisher.

Foam is also good for oil and fuel fires, should not be used on electrical fires and not a good choice for general house type fires. It also makes a horrible mess and is more for industrial type situations.

CO2 is good for electric fires, it will put out oil and fuel if you are really quick and get the fire right at the start but there is risk of reignition as the CO2 disperses. not much use on oil fires once they start to take hold because of the reignition factor. Not sure how CO2 extinguishers fit in with environmental concerns nowadays.

We carried water, foam and CO2 extinguishers on the RN ships, powder wasn’t a big thing back then.

Great bike, I had a 1964 CB 72 250 back in the day, (the CB77 is same bike bored to 305cc),  I bought it around 1966 from Ben Lloyd’s in Crosby Liverpool where I am from. I was in the Royal Navy and used it as weekend transport between Portsmouth and home when I wasn’t at sea, it never let me down or missed a beat, I loved that bike. I replaced it with a 1966 Triumph Bonneville about 3 years later because I wanted something faster, it was fast but only when it was running which wasn’t very often, learned my lesson and stuck with Japanese bikes after that.
Good luck with the recommission and enjoy the bike.

I had a similar situation with getting a NOVA for a 1979 bike that magically found its way into the country a number of years ago.  I thought it was going to be very difficult I phoned the NOVA number and they could not have been more helpful. I told the lady I spoke to what I believed the story of the bike was and that I had bought it with cash and had no receipt. To my surprise she just said ‘oh I know what you men and your motorbikes are like’. I had to send a letter with vin number etc and got the NOVA about a week later. She added a closing comment of ‘and good luck with the DVLA once you get the NOVA’ .

I have a 1962 Triumph T100A I am very slowly rebuilding, the bike has Whitworth and BSF fixings, with some British standard cycle threads thrown in and yes as mentioned studs with different threads on each end.  Your 70s bike might be different I think they were trying to go with UNF and UNC fixing which use AF spanners but it was all a bit shambolic so I guess expect what you get.   Do get the correct tools, you can still get Whitworth spanners but Whitworth socket sets are hard to come by maybe go down the second hand route.

I would highly recommend TMS in Nottingham for spares they may not be the cheapest but they are very knowledgeable and parts are of good quality.

I like taper head bearings and feel they are the best so I bought a taper bearing kit for my 550, I had problems fitting it, same as others have said ‘to high not enough thread left at the top’  not protected from elements. I decided original setup had been ok for 50 years so got new bearings and went back to that, everything fits as it should no problems. So my advise,  take the easy path.

I’m in the middle of a 550 rebuild and it’s interesting to think about my approach. It was never planned as a full rebuild, but starting work on it made me realise how bad the bike was, so I turned it into a full rebuild one day by taking it to pieces, so not much planning there. I definitely did not take enough photos which has cost me time but has given my brain cells a good workout.

My rebuild method has been breaking it down into small projects, the projects aren’t random but are related to the order I am working to. I do deviated occasionally to give myself a change when the bit I am working on isn’t going well,  or if I am waiting for parts.  I do try to keep closely to my rebuild plan though. 
An individual project can be something small like cleaning polishing and painting the underside of a mudguard, fitting it would then be a separate project. Or it could be bigger project like rebuilding the forks and all their associated parts. Eventually all the small front end projects will result in the front end being rebuilt. However by making it into small projects you are continually having results which make you feel good and that you are getting somewhere.

I had a few blue V5s to get changed over a few years ago and thought I had better get it sorted when I read you could be fined for not having done the change over.  I phoned up to enquire about it and got quite a difficult woman, she told me she would have to put me on hold and transfer my call to the penalty department. I ended the call then waited a few days and phoned them again and got a really helpful guy, he told me they should have been done a long time ago but said to send them in and they should be ok. I sent them in batches of two or three at a time over the next couple of months and they all got changed without any problems.

I have had quite a lot of dealings with the DVLA over the years and they have generally been helpful, I would say if you phone and are polite they are ok with you,  if you phone with attitude then you will get attitude back. If you phone and get an unhelpful person then end the call and phone again latter.  If you phone and there is a long queue you will be offered a call back, go for it as it works well.
I haven’t had reason to phone for a while so maybe with the way things are going you can’t even phone them now🙄.

I have never had anything I have sent to the DVLA get lost, there does seem to be a lot of post codes, for different departments I guess, so make sure you have the correct post code for the department you need.

I have the shimming tool but its edges where it contacts the buckets are getting a bit worn and sometimes it slips!! I will be using it soon as I am just putting this head back together.