Does anyone out there own a Hohner XK250 or XK251 fretless bass? I have what I believe is an XK251 that I've owned for many years (I bought it used way back when), but as I was doing some maintenance on it the other day, I suddenly became aware that other than a small sticker on the back of the headstock that says "Made in West Germany", there is absolutely no other identifying tags on the bass at all. No logo on the headstock; no serial no. in the f holes, nothing. Where is your serial no. or Model no. located? She's a great bass that I've had for quite some time, probably around 30 yers. She's my go to when I want a fretless.