I'm going to add to my last comment that I used to make wallets with some people who had made their embossing press using two heavy rectangular squares of steel with a large worm type screw thru them. You just layed your cased leather on the bottom slab of steel,put the plate on top of the leather and screwed the top slab of steel down tight onto the bottom one. Very similar to the early printing presses. These are very easy to build and there is no end to the variety of materials you could use to build one. While not fast they work well and it would depend on the size of the leather you are embossing what size press to build. When I do use an embossing stamp I use just a plain old C-clamp on a hard surface to transfer the image especially on the new 3D stamps,but as I said earlier I'm not a big fan of embossing and since most people don't know the difference between handtooling and embossing it has created difficulty getting a fair price for something you have spent hours creating by hand as opposed to stamping it out in 10 minutes.