If you are not cutting out lots of patterns you can use a scalpel-they are super sharp and disposable (Amazon) and is what I use on 6/9 oz Herman oak leather for my folding knife holsters- a saddle maker I know just uses the cassette skiver blades inserted into an exacto knife body. I hardly ever use my round knife anymore. For long cuts like putting a square edge on a side prior to making belt blanks I just use a straight edge and a rotary cutter.
Another source of quality handmade leather tools is Bob Douglas (Quality Douglas Tools, Sheridan, WY), he’s a small shop so call his wife Lee 307-737-2222 or email her douglastoolswy@gmail.com and they are very helpful, his copper saddle rivet setting tools are the best I’ve ever used and his hand tools are great as well.
Another source of quality handmade leather tools is Bob Douglas (Quality Douglas Tools, Sheridan, WY), he’s a small shop so call his wife Lee 307-737-2222 or email her douglastoolswy@gmail.com and they are very helpful, his copper saddle rivet setting tools are the best I’ve ever used and his hand tools are great as well.