I have a circa 1992 58mm Bladeless with tweezers and the small pen. I also have a circa 1974 91mm Fisherman with tweezers and toothpick. Not surprisingly, the removable tools from these different models are not interchangeable. The old Fisherman tool slots are the same on both sides even though the tools aren't interchangeable. The tool slots on my Bladeless are different. The tweezers slot is maybe 20% wider than the pen slot. Is that the case with all 58mm models? I don't have a Classic SD to measure, but are the slots for its tweezers and toothpick different widths?