Anyone ever make a pocket floorplate for a M98 out of 3 pieces (2 florrplates and a spacer).

not exactly - i just made it for the 550 express -- it worked, which literally the nicest thing i can say about the results

Jim Wisner makes an extended floorplate that only protrudes 1/8" more than a normal floorplate. My Winchester 70 holds four .416 cartridges with the extended floor plate.