With that in mind...
The 9-T-79 showed up tonight, and she's a beauty! Cabinet is just as nice as I thought it would be based on the pictures, only a chip or 2 of missing veneer by the feet which is about typical. Couldn't get pics of it in the darkness, but by the headlights of the car I yanked the chassis and picture tube. Chassis is nice and clean, a few tube replacements but the horizontal output and rectifier look original. Picture tube is an RCA Service Co. 19AP4D rebuild, which tests at the top of the scale with only 4.5 volts on the heaters. Life test doesn't even move the needle.
Must not have been run long after it was installed, the whole thing looks to have been mothballed just after the CRT was replaced. Lady said it still worked, but I'm not gonna try it.
Metal tubes FTW!
Tomorrow I'll get some cabinet pics up, then try to fit the proto chassis inside and take some measurements. It looks like it will fit, but I don't think it will make a good choice since the CRT is so much larger than the developmental one. It may mean some fooling around with mounting, we'll see tomorrow at the buttcrack of dawn.