Worth checking the valve timing too: at top dead centre on the non-firing stroke that the exhaust valve is probably just closing and the inlet just opening.
If there is overlap (unlikely on a vintage sidevalve), it's usually evenly spread, so that both valves are just open at TDC.
If there is no overlap (i.e. there is a period where the exhaust has closed, but the inlet is yet to open) then the exhaust usually closes at TDC, and the inlet opens after TDC - maybe 10 or 15 degrees. Strange but true.
It's good to know what the manufacturer intended, but realistically the valve timing on an old engine is rarely to exact spec due to wear and manufacturing tolerances.
R's clearances will work fine, although I'd leave the tappets a bit looser - maybe 10 thou. I cannot tell a lie: I've not used a feeler gauge on a side-valve tappet for years.
Have fun, and let us know how you get on.
Leon