TA cups of the era are marked, though not in the conventional sense. An English thread is designated by two rings on the fixed cup. A French thread is designated by a single ring and an English cup has none. There's also a difference in the knurl on the lockrings for the adjustable cup. English has a straight knurl, French has a diamond knurl and Italian has a diagonal knurl.

The rear derailleur and crankset are firmly boom era, though these may have upgrades after the repaint, as those 114mm rear dropouts are standard for a 3 or 4 speed freewheel or possibly even an IGH! The frame clearly has the 2nd generation Simplex integral dropouts. I'm not sure exactly when these came out, but believe it was circa 1962, when they brought out the Prestige. Five speed frewheels were standard by this time (and even 6 speed was available), so the spacing is still a bit curious.

Given the apparent age, the dropouts and lugs indicate an upper end frameset. I'm surprised nobody has asked for the seat post size, to determine if it's Reynolds 531DB tubing.