Honda-SOHC

Well done you......... I've only just seen this post and I've always thought it can't be beyond the wit of man to come up with a way of saving solid downpipes and cutting off rotten silencers......... and you are that man, you've proved it !
Looking at the Classic Bike Shop site I'm guessing that you've used the Bonneville silencers and cobbled up some bracketry  ?   (Beats spending 800 odd quid for iffy replacements).  And they don't look out of place.
  PS Like that number plate !!

Condensers are new replacements from DSS........... It was one of my first suspicions......... suppose I could have been unlucky and got the only two new dodgy DSS ones on sale !! 

PS One driver arrived from Japan super quick but the other one I'm still waiting for (unbeknown to me a different supplier) but I must admit a very nice fit...... work a treat.

So did I !!

Thank you each for that........... I'm going out to play with it again now and let you know how I get on.   

That's very kind of you Ash.  I've seen your workshop setup on Youtube and it's enough to disturb Dr Frankenstein.  If you could email me your address and I'll remove the coils and get them into the post next week hopefully. (Life is a bit "full on" at the moment !!)

As Bryanj say's, I shall also double check the insulators.

Thank you all.

Update......... I've just ordered JIS drivers on Amazon (although I won't get them for a few days). 
Spacers....... I'm sure they're correct but now you've sewn that seed of doubt I will double check !
Kill switch......... Will trace and test wiring inside headlight.
Today.......... Back aches, knee aches but will endeavour, given half a chance, to get out there again later and follow up on all these latest suggestions !!

Hi Seabe, Sadly I don't have a multimeter but "collared" the boiler repair man who used his meter to check. (The coils were off the bike at the time).  I made a "buzz box" to check for continuity from the blue to the 1/4 points and ditto from yellow 2/3 which at that time was fine.  Put the coils back on, tank on etc., but had no spark from either set this time.   Checked again from blue and yellow and now makes no difference which side I get a buzz from everything so thought I must have a short circuit somewhere.
I confess, I've not done a direct +12v to coils but ?  Without the equipment I'm having to think of simple solutions which, I'm sure it only is, because it had been running and lost pulling power, faded but would restart before doing it all again.  So, looking in the Haines book for "loss of power" took me on this route.  (The fuel had been in the tank for about 8 or 9 months with added stabiliser but I topped up with about a gallon of fresh before draining it all out and replacing once more just in case stale fuel was my problem but as you can tell I trailed off in other directions).
Thank you for reading my tale of woe !!
PS You're right, "Hairygit's" comment about the kill switch went through my mind even though I rarely ever shut down using it but the sad thing is I can't get the screws undone without drilling them out.  (Don't you just hate crosshead screws ?). 
PPS  If I'm understanding correctly, I've just tried +12v directly from battery to the Bk/Wh coil wires (and neg to earth) and looked for spark at points which wasn't there !!  Uh!