The Brits in general are not as nuts about original condition (reblue, re-CC, stock redone) than are American collectors. As Ted said, that's considered more a matter of preventive maintenance over there--which they tend to look upon, with their guns, more like we do with vehicles (and less like we do with guns, which quite often is not to take them to a gunsmith unless something is broken). If the work's been properly redone and in the British fashion, to me it shows that the previous owner took proper care of his gun.
Interesting thread this. As a Brit and having recently got a lovely Darlow 16 bore sidelock "redone" - as in reblacked barrels, rechequering cut and fully serviced and regulated - I did not think twice as to undertaking the work. The gun had not had as regular preventative maintenance as it should have done, and I wanted a gun I could both use (tough to do properly with worn chequering) but also which looked the part as it would have done when first made. The reblacking was done expertly by a very experienced barrel blacker, and although the work took time, it was done very well. I can now look forward to using the gun for years to come, and by taking care and getting it serviced internally every two years, I should be able to pass it onto my family in the future. I don't feel the work done has in any way diminished the value and in some respects, the feedback I have is that it has actually
added value.