spekesoftly
No, those runways were really 750ft wide! At Manston you can still see the original concrete under and around the built-up modern surfaces of the current runway and parallel taxiway. I've never been into Woodbridge, so can't comment on what remained of the WW2 runway. Carnaby still stands out like the proverbial doggie's danglies from the air, even though much of it is covered by factories and car parks.
Yes, I was a JP3 man as well ('77/'78), and flew from Elvington many times.