I believe your bike is a Magneto (Magdyno) model so you are unlikely to find any ignition timing marks, as the information I have from the factory manual says the timing was set by using a marked rod inserted into the plug hole and resting on top of the piston to show 5/8" BTDC on the compression stroke.
At that piston position the points (points gap should have already been set to 0.012") should just be opening when set FULLY ADVANCED.
The moment of points opening was generally found by inserting a cigarette paper between the points, when the points let the paper go that was the opening point.
Plug gap: 0.022"
Tappet (valve) clearance cold:
"Push rods free to rotate without up and down movement"
Bruce Main-Smith should have a photocopy manual available.
