There are still a lot of people in the AM community building amplifiers and high power transmitters that use tube.  Over on the AM Forum (AMfone.net) they have a for Sale and Trade page that list lots of items like capacitors, transformers and tubes.

Also the Audiophile community tends to be big on those old oil filed capacitors too. A lot of the Aerovox and Sgngamo and Sprague sell for $50-$75 just because of the sound.

Ray F/KA3EKH