National Model 90 head schematic/info?

[Valveboy]

Hi folks. I just found a National head in very sorry condition. This is just a head only, no speaker cabinet. The faceplate says National Model 90 on it. The serial number sticker is long gone from the back. It has a pair of 6L6's and 5, 12AX7's. The reverb tank appears to be made by Hammond. Two channels. Controls on the front are: Volume, bass, treble for each channel plus tremelo speed, tremelo intensity and reverb intensity. Also high & low input jacks for each channel and jacks for tremelo foot switch and reverb foot switch. Also standby, on/off and line reverse switches. I'm especially interested in finding a schematic but also any literature with photos showing what the thing looked like before years of sitting at a municipal baseball diamond used as a PA system. It's in for a serious cosmetic overhaul so I'd like to get it as close to original as possible. Thanks! Dave

[Valveboy]

may be Supro S6651 or S6698

I'll have to check closer but both schematics look similar to what I have