Most valve radios that I encounter seem to be from the 1950s. I'd guess that more were made during that decade than any other. Many of these sets are fairly basic affairs with two or three AM bands, a crystal gramophone pickup input and a single ended pentode output of perhaps a couple of watts. These sets can often be had for just a few pounds, or even free, especially if they don't work, and/or the case is scruffy, knobs missing, etc. From such a set it's fairly easy to salvage parts that can create a simple valve amplifier - personally I'd remove the components and create a new chassis, nothing flash, a cheap aluminium box looks fine.
Every now and then I find something a bit better. I bought a 1950s McMichael set with push-pull 6BW6 output for the valves and output transformer but realised it also had a very good power supply with choke smoothing (CLC) and decent 5V valve rectifier. It even had fused HT (using a panel lamp as a low current fuse). So I'll transfer the components to a new box and use it to power my pre-amp and receiver.