Oops, I incorrectly called it "search radar equipment" rather than "surveillance radar equipment" but it is the same thing.
SRE Approach = SRA.
I vaguely recall that the military AIDU Red book (En route supplement, or was that the yellow book? - it's been quite a while) changed from using the term SRA, to SRE for a while and then I think it changed back again. Possibly around the time they went from QFE to QNH then QFE again?
However, Pooleys now call this type of approach an SRA and it IS still available at St Mawgan. Interestingly, irrespective of which runway is in use, the SRA inbound track is 304* in this case. The St Mawgan plate also gives "circle to land" minima for occasions where the wind favours another runway; as I said in my first post, it's an airfield approach, rather than a runway approach.