Here's an empty moving coil step up transformer box for use with your Altec Peerless 4722 transformers, or other transformers with identical pin out. This is a custom engraved box using high quality Belton sockets. It has high/low gain switches to select either the 4722's 38 or 150 ohm primaries, and a 3 position ground switch that allows you to ground the box to either audio channel's shield, or in the center position to just the ground post.
This is a newly made box. I didn't include photos with transformers installed to avoid confusion about this being an empty box, no transformers included, but it has been tested with 4722's and is guaranteed to work (assuming your 4722's work, of course).
I don't currently have any 4722s available for sale, but I've added a couple of different pin compatible transformers to my auctions, as well as a box identical to this but including transformers, so if you need transformers as well, be sure to take a look at those.