Fred...the instrument sticker says Studio 403-SL hand written.
The only number I can find on it says DE-104 at the back of the headstock.
I seem to remember that the Guild salesman said something about it being a pre-production run or something like that. I bought it from Carl's Music Center in Lexington, Kentucky. Thought it was 63 or 4, but it could have been as late as 68, although I don't think so.
I'll be leaving for NAMM early tomorrow afternoon and am running to take care of last minute details, but will send you a photo after I get back.
Now you've got ME curious!
Thanks for the interest,
russ