Sounds like the case for a 410A/B VTVM or maybe the 200CD Oscillator?

Harold E. Johnson wrote:
Looking for an old piece of HP gear, can't even remember what it was
originally. Doesn't matter, just want the cabinet which can look like
anything as long as it's not dented or drilled upon. (Original was a
crackled brown) The item may have been their old VTVM, or possibly an audio
oscillator. The dimensions are 7 inches wide, by 10 inches high by 13 inches
deep. Most readily identified by having 4 banks of louvers sides and top.
They made some other items in a box a couple inches shorter and only 3 sets
of louvers and I don't need any of those.

Mni Tnx, Contact QRZ.com address

W4ZCB