Peter, I've got a BSA 45 receiver in my lap that matches Rob's exactly, including the D6E. The TR has been officially cancelled & I presumed being a 1945 rifle it simply arrived too late to be converted even though it was of the requisite accuracy standard. I have seen or heard of several others. Surpmil's is the only pre-45 example I've heard of. The other two or three were all V or X prefix 1945 rifles. Mine was obviously stripped down at some point but I obtained the body many years ago from our mutual friends at WWA & IIRC it didn't cost me a lot. I have no explanation as to how it acquired the D6E but I am sure as I can be that it is not faked.
If I can ever find my way around my new laptop (Windows 8 - very different to xp & Vista) I'll post pictures. I'll also post some of one of the early H&H conversions that bears the D6E on/near the knox of the barrel - something else that probably shouldn't exist but does occasionally crop up.