Oldgoaly gave you an example of the use of your tool. He used the punch to make larger holes in a leather belt in order to connect bells to it. Think Christmas. Sleigh bells on straps on horses (reindeer?) In order to put the bells on some holes had to be enlarged.
I see no evidence of handmade tools in this post, or of rarity. Unless it is Ebay "rare", which translates to "commonly found on every block in every city in the country with houses built before 1985"
All that doesn't mean they are not valuable.
These are common. I have examples of single punches like these I bought new. The Tandy Leather Company sells similar, but not single hand punches anymore. 5 or 6 years ago I was teaching leatherwork to a boy scout troop. I picked up 2-3k of their tools to have enough for everyone to be working on projects. (I opened a commercial account there for the best discount.) The store manager donated a big box of leather scraps for the young men to practice on.
I have a lot of leatherworking tools and have been learning leatherwork since I was 9, more seriously since I was 13. I pick them up whenever I can. They are always popular at estate sales, auctions, both live and online. The better tools (usually vintage tools) are sought after. Yours looks well made.
Although most hollow hole punches are the wheeled type or hollow punch, but you can still get the single size punches from specialty suppliers. Look for "Watch Band" punch or "punch pliers"
The pictures below are web clipped. They show solid steel handled rotary punch, a pressed metal rotary punch, a sewing punch (but it doesn't really core a punch, more like pushing through and stretching the hole out,) and a modern version of the punch you shared.
IMHO I like using the solid steel punch a whole lot more than the pressed steel type. The punch tips are screwed in and are replaceable. On many of the pressed steel rotary punches the tubes are pressed in and often press back out under use.
Chilly
