Make sure the action locks up tight and is not loose. Bore is critical for accuracy but they are easily relined. I bought an average or below average gun a few years back that locked up tight but had a sewer pipe for a bore. Had a cheap liner installed and it shoots fine for a plinker. Had to go to a taller rear sight to get it to shoot to point of aim. If I were to do it again with a gun with a better exterior I would have John Taylor install a TJ liner. Ther are the most accurate out there. I would also go for one with the best plating and blueing I could find. Rough ones are  plentiful. Nice, tight, original guns with good bores and good plating and blueing are harder to find and will cost more but be worth it in the long run.