We've got a couple of those at work Mk7. It was one of this type of offset conversions that was used to formulate the fitting of the cheek rest. The rest as they say, is history
On the subject of snipers as related to what Mk7 has said above and the like, there's a few lines in the Small Arms School weapon training memorandum dated March 1940 that states:
1 SNIPERS
As snipers no longer form part of the organization of the infantry section, the reference to their use in Para 1 and 2 on page 4 of pamphlet No2 should be deleted.
There's a few more odds and sode referring to the No3T and No4T rifles that I'll pass on when I get round to it