[AMRadio] AM364U

[CL in NC]

I have this audio amp stored in my collection that I've had for over 40 years.  I can't get to it at the moment but I am 99.9% sure the designation is AM364U.  This is a single channel audio amp, painted black,  600 Ohm input and output, a power switch, indicator and a mode switch for regulated output or straight through amplification, a VU meter and a large gain control marked in DB on an escuteon plate.  Contains 6SN7's, has the bottom cover but no top.  Was this used in any specific piece of equipment, or is it just a generic regulated output amp for air traffic control or studio use?  I ran across one of these for sale and the fellow had a price in excess of $300 on it.  Does anybody know if this is a sought after item?  What is you opinion of it's resale worth, $300 seems idiotic to me.

Charlie W4MEC in NC