Honda-SOHC

Ted, you have just completed something a younger mechanic would fail at mate.
By the way the chain whilst new was not an expensive one

It's marked DID on the links so I'm happy with it to go back on - it's not going to see much mileage in my ownership.

My target date was to have it running for my birthday - I've missed that by two days already. As I have my 400 to use I'm in no hurry to get it finished this month - it's still not very warm in my garage either.

Has a previous custodian filed teeth in them to id for each cylinder ?

Perhaps owned by a dentist previously 

On four of my eight exhaust collars (CB400F) I have these teeth  in the past I plain put them in the way they came out and thought nothing of it, however in recent months (many) it hasn't been me who put the exhaust system back on so I went to the CMSL site to see if that would help but they didn't exist there. By now I'm taking a closer look at them and they aren't exactly uniform, like my own damn teeth even. It must be some kind of damage or mod by a PO. Can anyone shine any light on this

Ted, you have just completed something a younger mechanic would fail at mate.
By the way the chain whilst new was not an expensive one

Good work Ted.

Its a skill that used to be genuinely labelled "Mechanical Fitter" in which the person assembling etc had to be adaptive with approach to competently build assembled machinery.

What could be "fettled" aspect of structural, mechanical and metallurgy, all part of training to cope with various components from disparate scource being built into one machine.

Quite a valued occupation, when we used to make things in this country