Leather Planner - Has anyone seen/used these before?

Hello all, I am new here and after watching a couple of videos I am going through a tool purchasing phase.

After watching the edge painting video, I was pondering how to get perfectly straight edges on joined (glued & stitched) panels prior to edge painting, but without resorting to sanding as a cut edge is recommended.

After a bit of fluffing around and searching on the internet, I found these cool little leather planers, same concept as a wood plane, but smaller by ALOT.

I was thinking I am going to try these out to see if I can plane joined panels to a "Cut" finish that is 100% perfectly flat and level - has anyone seen/heard of/used these before?

Also, they over both straight and curved bottoms, so going around corners and radiuses will be pretty easy too - so if they are the real deal, pretty excited!