A pre-model 28 is going to have some wear it was a user at all and most of them were users. That was what they were developed for. Are you sure about the re-blue? I have a couple of guns that I would have sworn were not re done and they were and vice versa. If it was good it shouldn't be a deal breaker.
I am more of an accumulator of used iron than I am a fancier of revolvers still covered with the original oil from the factory. Can't afford them, couldn't keep them.
From a written description the phrase "play in the cylinder" means different things to different people. Usually that can be taken care of fairly easily.
If you plan to use the gun, I would offer 450 and be prepared to go up to 525 in increments. If he can't make the deal let him be the one to stop the dealing.
If you want the gun, walk in and drop the money on the table and walk out with it and be proud you got it.

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Guero