Hi John,
Our local shoe repairer has replaced a number of long zips for me and repaired gunslips with holes in. They all seem to have sturdy sewing machines. Just thought it might be an easy fix for you...... Drop in with the gunslips next time you're in town having your brogues tweaked
Traditional cobblers seem to be dying out in these modern days of mass produced and cheap footwear, most of the ones I knew of around here are long gone and replaced with 'heel bars' which don't appear to have the skills or equipment used of old (but of course there will always be the exception I am sure!) But yes, a competent cobbler should be able to undertake such a job with ease.
Many years ago, I remember visiting an old retired cobbler at his home where he still did 'bespoke' shoe manufacture from his old shed - he had all the machines/equipment salvaged from his long term business when he closed down/retired. The quality of his shoes/leather work was exceptional and a pair of his shoes (made to order) were well out of my price range. I remember it a privilage to share his time with him, even at that time, he hung his head when he said what his Industry was becoming, the 'heel bars' and cheap mass production footwear literally put him out of business as he just couldn't compete!
Another cobbler that will be long gone now - along with his skills - so sad!
ASM
I am a Man of La Northumberlandia, a true Knight and spend my days on my Quest (my duty nay privilege!) and fighting dragons and unbeatable foe, to right the unrightable wrongs, to bear with unbearable sorrow and dreaming my impossible dreams.
The other place to get this done is anywhere that repairs motorbike leathers, they'll also have the heavy duty sewing machines necessary to do this sort of repair.
I notice you're in Sheffield. I know someone in Wakefield who is in the middle of setting herself up with all the right machinery to do this sort of work, she has 2 lovely antique cobblers sewing machines amongst others but I don't think she's up and running serving the general public yet. If you don't find somewhere better or closer in the next few days message me and I'll enquire for you.
If Alec at Bacsew can't sort you out, some other people to try are manufacturers or repairers of leather goods for the Equine trade, but be prepared for high charges.
Personally, I would purchase a suitable size zip off the Bay and replace it myself - given time and patience, it cannot be that difficult, the bag is PVC material not leather, using some suitable cotton thread I would hand stitch picking up the original stitch holes in the PVC. There are all sizes/types and colours of zip on the Bay!
The bag on my Centenary had the dreaded crumbling plastic handles - it's a common one and apparently, they even can deteriorate in the box. Took me some time but I found some suitable genuine leather handles on the bay, even colour matched to the tan/brown of the bag - okay, so not 'original' but actually, they look and perform better than the originals, so okay for me!
ASM
I am a Man of La Northumberlandia, a true Knight and spend my days on my Quest (my duty nay privilege!) and fighting dragons and unbeatable foe, to right the unrightable wrongs, to bear with unbearable sorrow and dreaming my impossible dreams.
I was fortunate in that all the Centennials I had, the three boxed ones had perfect handles and zips.
Whether the lack of exposure to sunlight helps preserve the grips, I don't know, but it would seem that if the guns and slips are used as intended, the grips deteriorate.