No one else has responded yet and I don't know but if the oil pressure light goes out after a lot of kickstarts without plugs you moving in the right direction.
A guide would be the Pressure Relief Valve setting, which my Original Honda German-language Honda factory manual from 1970 says is about 4,0 +- 0,2 Kp/cm^2 at 4000 rpm at an oil temperature of 80°C.
As an aside, my English Honda factory manual from 1972 says 56.9 lb/in^2 and 4.0 -+ 0.2 kg/cm^2, also at 4000 rpm and 80°C.
The fact that you're running 836cc should make no difference to the required oil pressure.
HTH
Thomas
PS While on the subject of factory manuals, I also have an original Honda CB750 Shop Manual Supplement dated 1972 covering the K1 but it seems not the K2 (yet)