I spent a long time searching for an MX, which I finally found.
My experience has been that MXs must be made of relatively thin metal compared to previous AP models as almost every example I have come across appears to have several dents or dings about the body, and the prism housings appear to be easily buckled out of shape through even relatively normal use of the hot shoe.
Of course, they are very light and "cute" and appealing (check it out with a Pentax-M 2.8/40 "Pancake" lens on it for looks): that's why I persevered
, and I use mine quite a lot.
On the other hand, finding a "minty" one could take forever.
In this instance, I doubt anything would be affected, other than the cosmetics.
(Check to see that everything else is OK, then ask for a reduction in price
)