Haven't seen a Datong unit in years which is surprising considering how popular they were late 70's and well into the '80s.
Don't tend to see such tech nowadays probably due to the advent and popularity of SDR software defined radio. Back in the day I had a 144MHz converter so I could listen to the old 'Part B' licensees on my CB. (SSB as well as FM)
Hope you find one but I'll bet they're pretty scarce nowadays.
All the best,