I just located an original BW CHRA... $420.
Andrew, I know you said before that installing that into my old K14 housing is something I can easily manage myself. But since this is quite an expensive item, I will just recheck this advice. From what I can see the basic housing is pretty indestructible and usable (otherwise why would all these "old turbo exchange" schemes be so rampant). Just the exhaust housing, the compressor housing, and the wastegate... on mine they all seem in good shape. but exhaust housing old and corroded.
[the problem with getting the full K14 unit from Germany is that it weighs 9KG, as opposed to 1KG for just the CHRA, and I would be asking some friends to bring it for me to avoid DUTY & POSTAGE]