For those of you who have old wooden blocks, like Merrimans, and can't figure out how to take them apart without destroying the wood, I've got a solution!
Merrimans (and maybe others) are clamped together by bronze screws that are virtually impossible to back out. My solution was to construct a make shift hollow drill from 1/8" round copper rod that you can buy at a model train store. Cut the rod to approximately 2 " and put in a regular electric
drill. Carefully start the drill over the bronze screw. It will try to jump around until it starts to cut the wood. But once it starts, it will cut cleanly through the wood along the path of the old bronze screw. I'm using new SS threaded rods which you can buy at most hardware
stores to reassemble the blocks after I've repaired everything.