Well, no 22 was a matter of ill-luck; Swindon cut the last one up by mistake!
Actually the idea has been batted back and forth a few times of a 1:1 scale scratchbuild of a 22. The drawings apparently exist (I heard Steve Beattie, amongst others, has a big collection of NB material), and there are quite a few V100 powertrains potentially available, it's not too big or complex mechanically, and now there's the A1 project to show it can be done...
[Edit: actually, on reflection, Fred Phipps is probably the 22 guru; he would have the lot!]
Mike