Ah, OK, I was looking for bombs developed for the TSR2 alone so I got side tracked.
Pail Lucas' book, 'Lost Tomorrows of an Eagle' mentions the 1000 lb N1 bombs as an alternative to the then current 1000 lb Mk 6 bombs, a blunter, more WWII looking weapon. Apparently the FAA already had large stocks of the 1000 lb N1 for use by the Buccaneers. The RAF wanted to use a retarded tail on the 1000 lb N1s but the MoA reckoned there was not enough time to do that for the N1s and the Mks 6,9,11 and 12 as well so they abandoned that idea.
The N1's official title was 'Bomb, HE, Aircraft, MC, 1000 lb, Mk. N1 with Ml 115 tail.' There are two photos of an N1 mounted on the outer wing pylon of a TSR2 on page 81 of the book.
Pail Lucas, the book's author, did the masters for that SAM set that Robert's got, and it looks like Freightdog may re-issue the set later next year too.