i'm replacing the wire, foot and plug-ins on the '48 featherweight i just acquired. since the cord has compromised insulation, should i worry about anything being rotted in the motor? it runs fine and i haven't seen smoke, but that seems a little too late, when you do. it's a simple machine and not too many places that can go all that wrong, but what should i be looking for? i am saving all the original parts, just want to be sure it's safe to use.