In Strattons book, it also mentions that not all the scopes had the W and B, the scopes that failed the Waterproof test, were only marked with a B, and were issued in dry climates, such as the African desert.
Mine only has the B. Its a 1946 Mklll.
The Indian No4T with the MKLicon scope doesn't have any painted markings. I wish this rifle could tell me its story, it seems that the Indian army picke up the vast majority of the rifles with the MKLicon scopes and refurbed them nonstop with little regard to matching up numbers and made up many replacement parts includeing mounts and chests (1/2 inch shorter than the Brit No 15 chest). bearhunter