Ok I have tried to work this out from some online searches, this website seems to be the best source:
http://www.islamic-awareness.org/Quran/Text/Mss/They are rather vague in what they say about dates, but this is probably because we cannot say with much certainty exactly how old these extant copies are. But the oldest ones are listed to date from "Between the end of the First to the beginning of the Second Century AH". Which means approximately
710-750 AD.
Two of the most famous old ones are in Topkapi, Istanbul and Samarkand. Whilst none of these manuscripts are totally complete, islamic-awareness.org gives the impression that there are quite a few manuscripts from this period, so there does seem to be a body of evidence to suggest that we can trace 99% of the Textus Receptus to the Late Umayyad Era (710-750 AD). But for anything earlier than that we have nothing.
It is interesting that the earliest Qurans seem to date from just a little later than the earliest coins that mention Muhammad or anything to do with Islam...