The object is a large metal circuit carrier with a phenolic board mounted underneath. It has 9 vacuum tube sockets, six are populated. Various BNC jacks and a multi conductor connector are mounted on the top. The string "404 COMPARISON REGISTER" printed in red on the top and the bottom.
Date
1951
Identifying Numbers
Model number
404
Printed in red in the center of the panel
Model number
601
Printed in white in the center of the panel
Other number
A8-1
Handwritten on a white sticker underneath the board