It fits!!
Very prompt delivery (from within the UK; so someone so far anonymous is acting as UK agent/supplier for Cooper Anchors). And it fits my (ie the Trouper 12's) anchor well, with a useful bit of a wriggle which will serve, I hope, to keep it in place in the extremely unlikely event of a capsize. The anti-ding-friendliness of the nylon construction is noticeable. There is a lump of lead or similar in the extreme nose of the blade. I plan to use it with a fathom of 6mm chain, otherwise synthetic hemp line.
....all of which is fine and dandy, but the proof of the pudding/anchor is in the eating/holding power. I will report again when I have tried it out.
Michael