I would buy just the priming station part for a Mec reloader.

Parts 72,73 and 74 on the following link. You do not need 75.

http://www.mecreloaders.com/order/SteelMasterPartsList.asp

74 is a steel cup with a post in the center. The primer sits on the post. The spring goes into the cup, and the primer seating pad goes on top of the spring.

When it is put together, the primer sits on top of the post, inside the donut shaped pad. The deprimed shell goes on top. You push down on the shell with a ram, and the spring depresses pushing the primer into the pocket.

Whatever you use for a ram will have to have a hollow spot inside the case to make room for the primer if it protrudes into the inside. Most do.

Note, the above is for priming the cases. I think you could deprime them with just a punch and the donut piece from above, or drill the right size hole into a block of wood.