Year: Body 84 / Engine see below
Description of problem (please be as in depth as possible):
Hi guys, my first post here. Recently purchased a mini that is a B-reg 1984 Mayfair. It was originally an automatic, but the chap who I bought it off said that the auto box packed up and he has replaced it with a manual box and engine taken from a 1991 Mayfair. I just now need to change the V5 to reflect this but I'm hving a bit of trouble locating the engine number... As a heads up, here's the engine:

(by the way, yes the oil filler cap is off as i was topping up)
All I can see is a code just to the left of the top of the dipstick that reads WFM 1026 4NW. Also, there is a part in plain metal (located just above the oil filler cap in the picture) that reads 'Mini Sport'.
Any clues?? All help is appreciated for this mini noob

(If you read the introductory thread there will be a few more basic questions coming your way (apols!)