I used to know 2 blokes who had Herds as they called them here in 1948 ,one with a big headlight and one with a SmallBradley
I don't know anything else about Reg Tonge.
As for headlight sizes, it appears confusing but is quite simple.
8" headlamp units use glass lens units that measure 8" in diameter hence called 8" and all early B's up to late 1947 used this unit.
The 7" headlamp unit that the factory refer to is the same unit that us owners call 6.5". So when you see 7" in the records its was a 6.5" diameter lens unit and the headlight shell was what measured 7" and this is the same unit that the later series C's continued to use. Why the different references to measurments for the same unit I don't know.
Around November 1947 the first occasional reference to 7" headlamp appears in the factory records and in early 1948 the factory started noting if 8" or 7" was been fitted. This continued right through 1948 and the last reference to a 8" unit been used is early 1949.
Now it appears that the Vincent factory just used whatever Miller provided on that specific day and so in 1948 both sizes were been used side by side and there is a factory photo of a row of finished series B's showing the mix of headlight units. So you cannot just assume a series B had the larger 8" unit fitted and need to consult the factory records to be sure.
Of course there was the exception of the sealed beam lens unit that was a later requirement for the USA market. This was a true 7" diameter lens unit and so a special conversion rim was used to fit it to the standard smaller headlight shell. These are clearly identified in the records.
Simon
Interesting all this , ATC is that referring to ATDC , ? We may never know