Gibson Uke 2

Hello,
I have a Gibson uke 2 with a serial number of 7655 38. I'm pretty sure it's from the late 40's or 50's. Does anyone have any experience deciphering the maddenly illogical Gibson serial numbers? Any help would be appreciated. Thanks.

Joe Spann at Gruhn https://guitars.com/users/joe is an authority on this info, having written a book about Gibson. Perhaps he can shed some light on that. Please let us know what you find and post some pics!