I saw one of those amp-in-the-case jobs at a store in Portland a few years ago. I was floored that it was a TUBE amp.
Yes, it was. For those interested, below is a link to the Owner's Manual/Service Data with schematic of the Silvertone case amp model 1449 and 1457.
https://www.silvertoneworld.net/schematics/schematic_manual_1449_1457.pdf

