The 72 stock was the first one to be named “tube train” if I reckon correctly. I checked the 38 as well and I can sit on any seats.
The Class 484 is the third train. It is otherwise known as London Underground D Stock. I think so anyway.
On that basis, surely the Class 483 would also count? Bringing up the number to 4. Or does that not count because of the 38 stock?
That is a good contender - I hadn't considered it. However, given that it was just a literal reskin, I'd struggle to count it.
I didn't realise it were just a reskin to be honest. I think it is the only other thing that is on the BCL though so as you say certainly a contender.