I was in Oxford in the fall of 1983, and "to go" was not said then. We American students all joked about "take away," as to us the phrase had an overtone of "Get this horrible stuff out of here." I first encountered doner kebab in Oxford (there was no Turkish food in Seattle then that I recall, and while we did have several Greek restaurants -- my sister and ex-SIL worked in one for years -- gyros hadn't taken off there either).