It would be very surprising, but not impossible.
I can’t speak for others, but if I were buying the scope from you I’d be much, much more concerned with how it performed optically than with that mark.
If you said it shows a very good star test or some other description of optical quality, I’d rather have it with the mark than a scope with soft optics and a perfectly clean corrector.
If you have used the scope and feel it’s a real performer, especially on planets, that would be another reason not to disassemble it. To me, anyway.
Again I no nothing of how the scope is put together, but taking it apart and getting it back exactly as it was might be difficult. Would you be sure the corrector is centered exactly as it originally was? Would you tighten the retaining mechanism the same? Could it go back slightly tilted to as it was before? These would be things I’d be more concerned with, but that’s just me.
And believe me, I know how such a thing can stick in your mind and never get out.
But from experience working on scopes and ham radios as well, there are too many variables and pitfalls that can and do happen when you ‘open it up.’
Again, just my approach, having been there.
- I assume when the scope is moved on its mount, you don’t hear anything rolling around?
- If you take the visual back hardware off the scope, can you see the mark from the back of the scope through the primary baffle - next to the secondary?