thanks, all!
for better or worse I went and bought a case of 12 liters of Amsoil Motorcycle Synthetic 20W 50 from a local wholesaler, had to go to his residence to pick it up

, all very odd.... anyway, $160 CDN all in, so about $13 and a bit CDN per liter. It is used by a lot of the local air cooled Harley crowd who claim it greatly reduces engine operating temperatures and it is supposedly the best thing since sliced bread........... anyway, the Amsoil is going into the 79 1200 and the 84 RGS, plus a couple of non Laverda's. The 82 Laverda 1200 TS Mirage Series 2 is still breaking in the fresh engine, so I also dropped by Canadian Tire, which had Castrol 20W 50 Grand Prix motorcycle oil on sale for $4.49 per liter, I bought all 5 liters they had in stock, asked to buy a case but they didn't have any more stock.
not sure how long I need to run the freshly rebuilt 82 1200 engine on dinosaur oil, but with fresh rings and so forth I am thinking maybe 1,500 + miles before switching to the Amsoil synthetic??
I have run the Amsoil synthetic previously in both the 84 RGS and the 79 1200 for extended periods with no issues and especially no clutch issues, and with frequent oil changes anyway hopefully there will not be any issues.
Paul LeClair