You'll have to do some digging on that amp. I thought the name Magnecord was associated with the old Magnecorder Tape machines, before seeing one in the bottom photo. Take a look at the date codes on the two capacitor cans on the CMK6 monitor amp. It would be a 4-digit code, such as 3461 or 1757. The code translates to week of the year (1st 2 digits), and the year (last 2 digits), so 3461 would be 34th week of 1961. That can help you date the amp, probably within a year of it's date of manufacture.
Ah, there it is in the cabinet with a dual speaker monitor panel above it in the photo. Line level input amp, I'd guess, though it also could be the tape head amplifier, so there would the the reproduce EQ curve on it.