Just read back thro' Jojo's previous posts. This bike is one with the early drop down spring loaded pogo stick stand.
Early A7 Longstroke had a single oilfeed to one rocker spindle, the exhaust.. Later variants do have the familiar two banjo feed, as always fed from the return line to the tank. Nothing to do with Oil Pressure relief or release. The PRV vents into the oil pump cavity, no feed to the cam as on later designs.
I've never considered bore lubrication to be a problem on these engines. The crankcase does not have the later trough to hold oil, so any oil from the inlet rocker box is immediately flung from the camshaft, hence the high rate of wear to the cam and followers but plenty of oil droplets and mist circulating within the crankcase. With a feed to the exhaust rockers, oil will drain down directly onto the flywheel to be flung up the bores as well.
For those looking for a new cam, the good news about the Camshaft is that they are readily available, as Forum members have found when ordering A7 cams for the later engine only to have a Longstroke cam arrive instead. Word on the Forum was that these were actually UK source, from David Newman Camshafts in Orpington, Kent, and marketed by Wassell under their Hepolite Brand. Feked show them, made of precious metal.......
Adding that oil hole as on later engines is certainly pushing the boundaries of our knowledge and will be interesting to follow up. The timing bush running clearance and a nice clean sludge trap/oilway are the keys to good consistent big end lubrication. Regular oil changes are a must for long life.
Looks like this project is progressing, so well done.
Swarfy