setting the ignition without marks

["Evangelos G. Makris" <emakris@hol.gr>]

It looks like the timing marks (notches) on the front engine
cover are missing so I have no point of reference to set
the ignition against.

Is there any "practical" method for doing it and be within
reasonable tolerances? This engine hadn't fired in two years
but after a few blades of fire erupting from the 1.75" HS6
carb throat and a lot of dizzy wiggling it started, wow!

So, any ideas on the ignition?
It is a 948cc A-Series beast (!) Low compression 9D-U-L-xxxxxx

Regards,
Evangelos