PCR Type differences
 

I have a PCR. I believe that it is a PCR 1 as it has a speaker built into it.

The audio stage is a 6V6 and there are several screened cables taped to one side as though they went to top caps that are no longer present.
There is no evidence of circuit changes below the chassis and the ends of the cables are taped over professionally, as though they were done at manufacture.

Looking at the EMER that I have a copy of the PCR had an EL32 for the last valve stage and an inbuilt speaker whilst the PCR 1 had a 6V6 and, I assume, an in built speaker.

Is it possible that I have a set that was at least partly built to work with either valve setup or has someone been in and mucked about, even though they have done a very professional job of it.

I believe you're describing a British-made set, which may not have made it to the US and will not be familiar to most of the members on this site. Perhaps if you list the brand name of the set and post a few pictures some one may recognize it. I suspect you'll have better results asking at a British radio site.