Jim,
Over the years as a machinist and toolmaker, I replaced many pins in things other than guns.
My experience suggests that I would press out the existing pin and decide if simply replacing it with one of the same original diameter (sans the wear) would do the job or if I needed to install a larger one.
If an original sized pin would do the job, I'd turn a pin a few thou oversize, harden it, then polish to size, press it in and dress to the reciever as needed. A curved reciever may need an extension of a slipfit diameter to get the pin aligned to press it in, then that would cut off after pressing in.
If a larger one is needed I'd take a standard reamer of a larger size, spin grind it down to the diameter I wanted, spin a pilot section on it (this is necessary for recievers like the LC Smith and others with contouring around the pin hole, but if the surface of the reciever is normal (square) to the pin, a pilot isn't needed), sharpen the reamer and ream the hole, make the pin as above.
One thing to consider: the high speed steel reamers aren't going to like cutting casehardened steel recievers. I don't have a solution for that other than annealing the whole reciever or somehow annealing the area around and in the hole.
