I love the 22B, and at the moment it would be the only car I'd replace the P1 with. Like you say, cat D will scare some people off, but for such a rare machine, I think you should be ok - particularly if you've got the documented history of a good repair. At the end of the day, every car that's imported from Japan (unless new) could quite easily have been damaged and repaired and there's no record in the UK.
Let me know when you're selling, and f you'd be interested in a trade with an R33 Skyline !! []
Dave