Opinions on swapping casebacks, metallurgy, production differences (same model number)

Hi,

I'm just wondering your opinions on swapping casebacks within the same model Omega watches, and to make things challenging, let's say one was produced in the first batch, and the other was from the last batch of that model number

Metallurgy / production-wise, the case and caseback assumably spend 50-70 years together, there could be initial differences, and even if not, they obviously go through different conditions, so even if miniscule, there will be material differences, but is it significant, any experiences?

Feeling-wise, it doesn't feel right to me, but I can't put my finger on why

As to why, sometimes a watch is just perfect, but someone deeply scratched the caseback, carved it, and sometimes another watch is deeply abused up top, polished, but the caseback remains completely untouched, it makes sense to make the swap, the sacrifice of one watch makes the other one perfect

Well... I would say that I could accept it if the initial caseback was destroyed... but as long as it is ok, even if deeply scratched, I would prefer to let it, it’s part of the watch’s life

quite a difficult dilemma, in my opinion its definitely differs from person to person what they will prefer.
if you care about a true authentic watch its definitely a no go, but if you want a nice watch which looks as good as possible i would definitely consider it.

The two case backs are metallurgically the same if manufactured with the same initial material; the properties are determined by the chemical compositions and the phase(s) in the microstructure which shouldn't change via room-temperature aging. But, often manufacturers do something subtle for example, even for the same reference depending on the production year inside is finished with or without perlage, adding a dot at a particular position with engraving etc. It's usually such a subtle point people find as a sign of inconsistency. So it's the best if the original parts are kept IMO.

I had to answer that question but it was a little more obvious.

I had two KO 2627 watches. One had a pretty good case, and a tired movement and damaged dial. The other had an overbuffed case, and a good movement and dial.

You can guess what happened next. The good movement and dial were moved into the good case. Which caseback?

Since the cases were otherwise identical, we kept the caseback with the good movement and dial.