There is one of those on e-Bay occasionally.
Usually quite a few direction finders on e-Bay at any given time.
I've got one from the 70's.
They usually cover the 200-530KHz range for long wave beacons.
Also, usually cover the AM broadcast band since you could DF off those in addition to/or if no LW beacons available.
Often they covered the "marine HF" band, often from 1.8KHz up to 3 or 4 KHz.
While there are not many marine NDB's still around, there are still some aircraft NDB's to be heard. Since you can use them with AM broadcast stations, they can still be fun to play with.
Do NOT plug it in. Even if it's in perfect shape, the capacitors often dry out. Plugging it in and turning it on may let all the magic smoke out of the capacitors in copious quantities. They either need to be brought up very slowly, or have all the capacitors checked and/or replaced first.
It looks like it's in pretty good shape, at least cosmetically. It would have some value to someone who was familiar with one, or willing to make it a project. Check e-Bay for current prices, but don't expect more than maybe $100 for it.
They are fun to play with, but they were pretty popular in their day, so there's a ton of them out there.