[Arran]

 In all honesty the two sets above the Philco look much more interesting, one is an RCA superhet and the other is some sort of early 1920s unit, possibly home made. But if it's the Philco you are interested in how do you know that it's a 511 and not the model 65 which is from 1929? Since it does not appear to have the matching speaker with it I would offer as little as possible, those Spanish brown model 65s and 511s seem to turn up quite regularly, another reason to have a look inside is that there is a metal cover over part of the chassis that often goes missing.
Regards
Arran