We would have replaced the leather up until a few years ago. Hood Leather Goods was our go to until they went out of business. Perhaps Classic Billiards can point you in the right direction if you choose to replace. If it were me I'd do a little internet search on leather restoration and stitch...
I have taken part in restoring several antique pool tables, because rosewood is practically bullet proof we only waxed them. Paste wax is easy to recoat, won't chip and offers a very natural look.
I love the Kling... Please share more photos in the future. Ball return makes this extra...