And since when did MR1's have tip tanks?
Always.....
4A if I recall (and someone will be along in a jiffy if I've got that wrong)
The 4A are integral to the airframe and therefore (one assumes) the same on every variant.
For infor, the things hanging on the end of the MR2's wings are not fuel tanks.
As PN points out...not three Nimrods, but two chasing something Soviet.
PN must have been there...to pick Kiev up from that shot!!