Hi, Yes Gates chassis but have inside phono and preamp stage. It was a modulator and stripped insides to refit. WE310a and 311A based with 6J7, Langevin OPT's-600ohms etc and etc... all fun
Some care to listen to the 16a in stereo. This means using the right and left channels on either side having the joined signals blend at the mono mouth. Why not. But when you understand the science behind the design of the 16a as clearly outlined in the patent where you appreciate that each side is actually half of the horn. As such, the added air columns are pretty much the same horn as the WE15b (two 555 WE15 horn). Both of the air columns add up to share the same mouth. But some enjoy it that way Read here 13audio.com/2020/01/05/solid-wood-western-electric-16a/
