Fork Bellows Installation

Atlas,
You might need the 71 onward gaiters if yours is a 1972 Commando. 97.1510 with that triple tree setup.
The 68 would be using this one:
https://andover-norton.co.uk/en/shop-details-2/15219/fork-bottom-yoke-c-w-stem
which the Gaiter would be attached to these below the lower yoke:
https://andover-norton.co.uk/en/shop-details-2/14956/fork-lower-yoke-cover-tube
The upper section of that gaiter would be shaped with a larger diameter than the fork tube.
here is the parts breakdown for a 68:

I may be wrong on this on earlier bikes that had this style of triple tree setup before 72's but I own 2 Combats.

How bout using a little heat from a blow dryer..that and some lube might help

To soften up the rubber bits, I've used this on my son's Seca carb boots. I also agree with the synthetic wintergreen to be avoided.
I told my son what I was going to do. He ordered the synthetic wintergreen. It didn't work. I ordered the natural wintergreen and it did work.

I can't get the video to attach. Look for information using NATURAL wintergreen oil to soften old rubber parts.
I used it on my sons carb boots on a 83 Seca 900. I told him what I wanted to try on them. He ordered the synthetic wintergreen. It didn't work. I ordered the natural wintergreen and it did work quite well.

I have some new gaiters on order that allegedly will fit. Thanks for all the advice.