What did the factory do in ‘75 to comply with the new rules?
Depends on what you "grew up on". For me, one down and three or four up is normal and shifting on the right is normal but I'm more used to the Norton pattern now.The right shift one up 3 down is the right way, just get use to changing bikes, after 50 years on the Norton as well riding Honda dirt bikes and modern Triumphs I have no problems at all riding with different side gear changes the brain just knows what bike I am on and come natural to me, it only takes a short time to train the brain, took about 2 weeks when I first brought my 75 Commando after riding the Honda dirt bikes before it came along.
As we get older sometimes the brain will have a cock up and might make a mistake and to be honest I have recently jumped on the Norton and even with the right foot I down shifted instead of up shifted, bit of a brain fade, but that was the first time in 50 years of riding the Norton other than when I first brought it new, the first ride from new just around the corner from the dealership a bus stopped in front of me and I hit the gear lever instead of the rear brake, lucky there was no car in the next lane and I swung around the bus, but made my heart rate drop, was a wake up call to get use to the change in foot and gear position after a week or two had no problems as I was taking the Honda dirt bike out every afternoon after work down the bush lands behind my place and the Norton was my only road going transport for the first 10 years.Depends on what you "grew up on". For me, one down and three or four up is normal and shifting on the right is normal but I'm more used to the Norton pattern now.
It makes for fun sometimes. A while back I came around a corner on my Trident forgetting that I wasn't on my Norton, and downshifted while grabbing a handful of throttle. A spectacular wheel stand resulted - I didn't know a Trident could do that!
I think it is easy to switch sides, switching the pattern on the same side can be more difficult.