I bought a '52 AO Telecaster on Craigslist and when I got it home I noticed a weird mark on the back of the headstock. The body looks right, actually, everything looks right. I took the pick guard off, no issues, neck and body cavity look right. The place where the neck anomaly isn't where a "MX" number would be. Neck and body dated "Aug, 18 2012" leads me to think it is an AVRI model. Serial number V1204220. What do you guys think?