I would get it rebuilt before I would use it. I have Ken at AutoTurboDiesel down the street from my Phx yard. Or I could send it off to a reliable builder. Maybe sell it. These flow a lot of air.
Yes they do, they are not that bad to rebuild, I just did my HT4B. The kit from holset is around $300 I think, but smaller exhaust housings are pricey and getting harder to find, and judging by the pic that has a 40cm+ housing being it is twin entry.