rs,
I have received from another source the following interesting and informative input
In my very early RAF days I was an Armament Fitter at Gaydon which, apart from Victor/Valiant aircrew training had a nuclear role and we routinely practiced with these loads both in inert and live form. However, all publications relating to these and much of the airborne equipment were classified as SECRET or above and seen only our leaders. But, the then current nuclear bomb (Blue Danube) was covered by an inclusion in a RESTRICTED Air Publication as Bomb HE, Medium Capacity, 10,000-lb.
If there was - in the RAF inventory - a 1000 lb 'N' Bomb containing a chemical agent then I expect that too would have been classified SECRET and the technical documents given limited distribution to potential users but a 'cover' bomb described in an AP with a lower security classification.
Redsetter is mentioning two classes of Bomb. A 1000 lb 'N'' (original) - probably the new design casings filled at Randle and - secondly - a Cluster version to supercede the original.
I can't see HMG going to the trouble of designing, manufacturing, testing and filling just to supply an overseas order although - if subsequent HMG policy became no CW - they may have considered selling them on.
I think it more likely that they were intended for HMG use and that when the perceived 'need' passed that they were secretly disposed of and the documents destroyed or sanitized.
Colin