For those with libraries of old WTT's

I have June - July 1952 "Uxbridge Area" LT bus and rail local timetable (price fourpence)

The first Mon - Fri Mets out of Uxbridge were the 4:55, 5:12 and 5:26; but the 6:36 was the first through to Aldgate
The 9:07 and 9:20 were Moorgate terminators
The first out on Sunday mornings was the 6:53

On M to F the last two back to UXB left Baker Street at 00:04 and 00:26
On Suns the last one left Baker for Uxb at 23:55 and called at Dollis Hill, Willesden Grn etc too!

I don't know, this is a UXB area public timetable, not a WTT. However, it does show the only 2 x Moorgate morning starters to UXB (and don't forget that this is only an UXB area timetable, so other Moorgate starters could have gone elsewhere) were at 07:58 and 10:11, also there were 3 x p.m. starters from Moorgate to UXB at 5:26 p.m., 6:28 & 6:44 (There was no 24 hour clock here then)

It also shows the 12:30 from Princes Risborough to Paddington called H Wycombe 12:47, W Ruislip 1:08 GREENFORD 1:18, arr Padd 1:35 p.m.