There is so much we don't know for sure about this Great War kit. That is one of the things that I find fascinating. Enclosed a few pictures of some of my scopes. Note one of them is also a T prefix. I can't remember if it was from TBS or whether it may have been a conversation with IDS but he mentioned that most of the serials on authentic SMLE snipers of the Great War era are all near the beginning or the end of the alphabet. Of course, whilst it is an interesting observation, it may simply be chance, as so few original rifles survive. Of course, rifle serials engraved on scopes give us more data to chew on.
I also no longer believe that only Enfield produced SMLE's were converted to snipers.........the Charnwood Ordnance rifle was I am pretty sure correct, & was built on a BSA receiver. I have an Aldis scope which bears a serial number that was allocated to a 1915 LSA. However, there is no doubt that, of the few genuine surviving examples, most seem to be built on RSAF Enfield production.
Note the scope with the 'wrap around' range drum saddle. I own only this example, but know of one or two more. I have little evidence to back it up, but suspect this is a quite early variant. One way one can get an idea if a scope is early is if its rings bear the 'Patent Applied For'. Clearly this suggests (probably, relatively) early production. This is only from my rather faulty memory, but I cannot recall off hand seeing any of the 'long cone' scopes with 'Patent Applied For' on them, which suggests that they are later than the 'short cone' type. I have often thought that the point at which the cone flattens out to the threaded part at its front is a weak area in the design, & I have seen a couple of scopes where this area had broken away. The 'long cone' type is much stronger here, & so it would make sense that it came later as a design improvement. However, this is just supposition on my part.....