Spot on well done lovely job 👍

The one with the larger hole would go into the exhaust side ,👍 Roy

You allready have the disc and sleeve etc , shown in your photo , wind that in with crank nut , Roy

Good morning according to all my data standard inlet valve head size. BSA a65 1966 /72 is 1.598 ,  guess your may have been opened out ?? Regards Roy

Do you know what make/ brand piston is fitted ,as there are some pistons on market that require a lot more piston to bore clearance , if possible ask what clearance they are setting at , regards Roy

I have for Many years used Morris 20/50 all year round ,in engine  with No problems at all , I have a fried who does massive mileage per year , tour the continent etc also morris 20/50  ,

Also with carol nash very fair to me in my opinion,

TAPPET clearance would be approx 0.003 so it wouldn't  take long before loss of compression with valve being partially held open ,due to valve recession,,
Should the head be off at moment I would suggest to have harden lead free seat in now ,only exhaust side needed , jobs done properly,

Regarding lead free conversion,if using cast iron cyl head the seat area will,work,harden and quite likely have no or very little valve recession ,however if valve seats have just been refaced hard skin will be gone and then it's quite likely to have valve recession, so either fuel,additives or hard seat inserts fitted ,

I have found some pattern plates are just not up to the job ,changed to surflex brand then ok

0.001 > 0.0015  others may want to differ ? Regards Roy

My opinion is sort it now ,either change for a good s/h or send off for stelite and re profile ,Roy

Just like to say I have had/ used / fitted many of the wassell supplied Vape units and to be honest have found them very reliable, the latter one have a much greater voltage range and less likely to give probs should the battery voltage drop , that's my opinion anyway ,as ever all the other electric components and wiring on machine should be in tip top order , over the years I have had coils play up particularly if they hard not in air flow or get to hot ,
Hope you get to the bottom of you problem ,regards Roy

From my personal experience with these eccentric spindles , I would view through inspection cap to examine exactly where the rocker arm is over the top valve spring coller and if need be adjustso the arm moves away from coller , I have worked on many engines where the arm has hit the coller ,the collets have jumped out and you can guess the rest ,Roy

Well in my opinion I would either use resistor spark plugs and Non resistors plug caps ,or the other way round , but that's only my opinion,regards Roy