Some more.
Electronic Brokers, had real test gear but their catalogue was the only way of knowing what was available.
Was it Bi-Pak in Southend? Or Bi-Pre-Pak? Used to buy lots from there, amazing how much you can stack on a motorbike even with a 60 mile journey ahead.
AH Supplies in Sheffield, just off the M1 then the A52? Visited there a few times from Suffolk.
Mustn't forget Arthur Sallis Radio Control in Brighton, bought lots there.
Anchor Supplies in Nottingham Cattle Market, still there I think, also at Ripley. They got hold of a load of 141 spectrum analysers just as the EMC regs came in and started selling them much cheaper than at Johns Radio. Also a 466 which I still have.
Johns Radio, and yes, I remember the helpful lady who ran it.
Some place in Liverpool, just outside the city centre before they rebuilt it, last there it was a waste land of mud and concrete.
Wasn't it Ralfe Electronics in Pread Street? They moved outside town some years later.
Chiltmead, bought a Solartron 1212 scope there just after I started work in 1971, cost over £100. My cousin thought I was mad but that scope had some use until replaced by a 547 in the mid 1980's, Leicester Radio rally. Then my dad used the 121 until he died in 2008. I reckon that scope taught me more than the degree, at least in how to design things so they worked.
Other modern possibilities are Leavesley's at Alwras on the A38, Woods group in Crediton, Ramco in Skegness.