I have seen one but I believe it was a custom job!
I Have a .32 custom matchlock pistol that is a great deal of fun
on stationary Rabbits. Although you normally hit them in the neck
instead of the head, because thats how far they move between
the Poof of the priming charge going off and the bang of the gun firing!
The gun is deadly accurate though! 15 - 20 grains of ffg will punch a
neat .310 hole through a nice size cottontail.
I'm Working on a .32 Matchlock rifle now too.
If you find a .32 flinter, let us know where!