Out of all my refurbs I've only had two that had what I would call excellent bores- one '41 and one '44. Try as I might I can't see anything that tells me the barrels are replacements but we don't have much English reference material to go from. The rest have bores ranging from poor to fair while reblued on the outside, occasionally over quite deep pitting. My guess is that they were stripped down to the barreled action and barrels rarely, if ever, replaced. I agree that the quality of the work in the refurbishment was not great but it isn't all about appearance. I've measured bolt lengths on about 16 of these now and they vary by about 0.0150inch which tells me the arsenal was adjusting headspacing with different length bolts. Chumak mentions in the recent book (at least according to my idiot level translation) that the factories had longer bolts available to allow armourers to fix headspace problems which (according to the same author) were the rifles biggest serious mechanical problem initially. I should note that amongst my own SVT 40's I've had some with pretty weak bores that still shoot surprisingly well. My $200.00 Lever Arms Christmas special has a bore with very worn rifling and dark grooves but, after shimming the receiver-stock, it does 2 inch groups with milsurp ammo.
milsurpo