This sounds like a fine deal.
I loved using my Leica Cassettes, and when I had my IIIC, (they'll work in early, if no all, film M cameras too) and I liked that I could leave out the small cone shaped spring I used to push up modern film cassettes into proper position, when I closed the trap door.
The learning curve is no so high and most folks will appreciate the feel of the heavy brass, when compared to tin or plastic cassettes.
Good luck with your sale.
Eli