Gibson Amp date and circuit

[Billy Jones]

I've just aquired a Gibson amp that I figure had to be built around 1956. It has 2 P12Qs in it and looks very much like an oversized Les Paul. I've gone through the Pitman book and searched the web for some info but so far, no luck. The chassis number is 65633 and thats all there is.
The tubes are 5U4, (2)6L6, 6SC7, (2)12AY7 ,6SL7, 6SN7, 6J5. The Amp is about the size of the old Fender twin tweed.
There is no reverb but it does have vibrato with contols separate. The chassis was scrathed clean so there is no writing on the panel. 4 inputs, 4 controls and a 3 position off/on switch.
I was thinking of restoring it but is I can't get the info I need, I will build a Fender bassman circuit into the chassis.
So there you have it. It was also recovered in black and has Fender grill cloth.
It looks good and the chassis appears to be original inside.
Can you help?
Billy Jones (the old guy)