[Milsurplus] DF Set

[Ray Fantini]

That's a repackaged Detrola model 438 beacon receiver, introduced around 1941, very similar to the Setchell Carlson BC-1206. Same frequency coverage 200 to 400 KHz but think they had a different tube line up and IF frequency. 
I would assume by looking at the pictures that it was built around post war to maybe some times in the fifties being that not many would waste time with such old components beyond that. Also if you look at the pictures you will not see any components built after that time frame so would highly doubt that someone built that thing in the last thirty years. Taking this into account along with the vast quantities of cheap war surplus that was available in that time frame I would say that this was a good application of using obsolete technology and another example of how this equipment was repurposed and had a second life after the war. The alternative would have been the receiver and other parts being recycled or ending up in a landfill long ago, at least now possibly some Detrola collector may buy this thing and keep it on a shelf although I question the price.
RF