Omega Centenary Ref. 2500 vs. Museum Edition No. 5 Ref. 5704.60.02

When the watch was originally sold, that sticker would have been discarded, either by the store or the owner. Incredibly rare to see that today and I know that @MSNWatch would never remove it.

I wonder if there is a non-invasive technique that can tell if the engraving is there without touching the sticker?
gatorcpa