Well, the NME continued to publish their own charts into the 1970s or even later. However, the Guinness books and OCC use Record Retailer from 1960 onwards. I’m sure I’m aware of date78 - or am I? I have those programs which can date 78s. Probably from this forum. At least with the 1950s dates, the release dates aren’t likely to be hard to find. They’re probably all in First Hits, The Ballad Years or 45cat/worlds. I’d be very interested to see such a listing.