Here's a question for Fender buffs. In January 1970 when I bought my '69 Precision it had a strap button on the front of the headstock, near the tuners. I couldn't see any use for it and just took it off when I took the ashtrays and everything else off. I've never seen another Fender with a strap button there, so I assumed it was added by the previous owner. Any reason to think otherwise, i.e. is this something Fender might have done?