Really significant progress. Well done. It looks as though the issue with the blocks deforming is that although the vise is a nice big one, the jaws are still smaller than the blocks. Perhaps if you could get your hands on a couple squares of 1/4" plate steel to put between the vise jaws and the blocks it would improve matters. Even wood blocks would probably help, especially if they were hardwood and you have the endgrain against the frame blocks.