Yeah, I had a good laugh when a (fellow) internet "ExPurT" said that he's "seen many No4T rifles" which have had the rear sight modified for bolt removal.
I asked him to send me or post a picture of one as in looking at well over 100 No4 T rifles in person, and several hundred more in photos, I've never seen a single one which had a (properly) modified rear sight. Strangely not a single picture was forthcoming...
I HAVE in fact seen several which were modified by grinding the rear sight slide...obviously home done....and wrong.
And of course, most of the No4 T rifles I've physically had in my hands were sold out of the Britishsystem by the late 1960s, so it's quite possible that none ever received the modification...especially as most have early manufacturer codes (SM41 Singer manufactured ect.) rear sights....arguably likely original to the sniping rifle.