In other words I should have paid $50 or so to a real gunsmith to do what I did myself for 33¢.... I seriously doubt there's a more slip-proof-when-wet bolt handle than my stubby screwdriver handle--especially a free one.
Plus, as Red River Rick said, "Function is the key." This Mosin-Nagant has one and only one function: deer hunting in the rain. All I have to do is waterproof the primers via fingernail polish around their edges, and I'm ready to step into the woods in the midst of a tempest. All I have to remember is to keep the muzzle down so the barrel doesn't fill up with rain water.