Dogs and gears look pretty good, make sure the camplate tracks for the selectors and the index plunger are not worn too badly. When you shim the layshaft do it from the drive side. (the factory never did it!) As Gavin says, a couple of thou endfloat is all you want. All looks pretty good so far. If the rotor is out for any length of time a keeper is needed. (just use the stator) If you use a drop of loctite on the timing side crank locknut, you can dispense with the tab washer. As you've probably found out, it's easier to remove the oil pump and worm drive as one. You don't have to do that if you use 3 bolts rather than the original studs for the pump.
That's a 5/16 top end Gavin, probably cases too, that's why the hex nuts.
All the unstamped factory replacement cases built later I have seen come with the updated threads etc, ie cycle becomes UNF/UNC, the exception is some B25 cases made in 71 which had the narrow rear mount for 70 and before. There should be some small stamps on the crankcases showing a date, this started from 69 onwards or maybe earlier.
Head also appears to have small studs. Maybe a set of factory replacement cases?
No, the rear two are 3/8 as well.
That looks like a good set of barrels, the bores are evenly spaced, a lot of them were well over to one side. Pistons look good, measure them up and check the ring gaps and bores, may not need any new gear there just a hone and done. Spend a while filing a 45 deg lead on the bores at the base, it makes assembly much easier.
Yes--looks pretty good. Suggestion: put some rag or some pipe insulation around the con rods to stop them banging against the crankcase. Knocks and nicks start fatigue failures. Sorry Nick--not referring to you! (Brit humor).
Well, end of phase 1 today: engine is out of the frame:
Now I have removed all the case connecting bolts, but it looks to have been stuck together with loads of sealant, and it has resisted moderate attempts to split the cases. Before I get medieval on it, any advice for case splitting?