[Arran]

There are two more things that you need to watch for when you replace a tube socket, one is the distance between the two rivet holes in the chassis, the other is the diameter of the socket hole in the chassis. If the replacement socket is a used one salvaged from another Philco chassis there should not be a problem with either dimension. There is one more thing that you need to be aware of in case you buy a new socket from China or from one of the countries of the former USSR, and that is the mounting system used. There is a design of octal socket where the socket can be mounted either on top or bellow the chassis depending on how you use the metal bracket that comes with it, an old radio chassis may not have enough space underneath for the bracket, and there may not be enough height inside the cabinet to mount it on top. These sockets are available in both porcelain and in Bakelite. Another think to watch is the fact that these countries frequently give measurements in millimeters, which is fine, but make sure that the conversion is right before you order.
Regards
Arran