'39 ES2 Questions, advice needed

Hello, I looking for some advice and guidance. I've just bought a 1939 ES2 , suicide stand model. It hasn't run for well over 10 years so I decided to strip the motor down and make sure everything was in order and give it a thorough clean. 

I don't have a good size exploded diagram of the engine or a dedicated manual, I do have a book by WC Haycraft which is very helpful. I have a few questions I hope you guys on here can help me with..

1. I am replacing the main bearings, my bike had two ball bearings races on the drive side and one roller on the timing side. What is the correct placement? RGM sell a bearing set with one ball and two rollers (looking at the photo) Also the spacer between the two races, which way should the notches face, crank or drive sprocket or doesn't it matter? 

2. One of the tappet contact pads was loose, as there isn't any up and down tappet clearance necessary do you think a drop of loctite bearing seal would do the trick? If not any recommendations? 

3. Should there be a gasket on the timing cover, I can't see one on the diagram I have?

4 should there be a seal of some description between the oil pump and case and cover?

5. Mine had an aluminium head gasket fitted, I want to seal it as it was intended. I have to 'lap' the top of the barrel to the head... Now this is where I am not sure... before tightening the head down should there be a slight cap between the head and barrel which disappears when tightened or should there still be a 'gap' after the head is tightened? (Between the surfaces of the barrel and head where the head gasket was).

Any tips on measuring the end gap with the diagonal ring ends? I always seems to move the rings when trying.