Some time ago I noticed my gear-lever gaiter was starting to look a bit scruffy and dog-eared. It's not actually made of leather and the leatherette was starting to show the fabric through it where it was repeatedly creased.
I acquired a new one on eBay made from leather, from a seller called "the-tuning-shop-team" and I'm very pleased with it, however...
Some time ago I had an issue with the gear-knob unexpectedly coming off in my hand
and that was remedied using PTFE tape, but when it came to fitting this new gaiter I couldn't get the bloody knob off to get the gaiter on!
I eventually decided to gently stretch the leather over a period of days, by sliding it over the gear-knob as far as it would go and just leaving it for a few hours followed by more manipulation and further stretching.
Repeating this eventually stretched the leather enough and it finally did go over the gear-knob and without bursting the stitching or damaging it in any way. Stretching it made no significant difference to the way it fitted around the bottom of the gear-knob with the plastic tie-wrap, and overall I'm very pleased with the way it fitted at the base.
I should mention that the old gaiter was simply cut off