The Trinity Midnight is a 27 turn motor, one of the last Trinity made before they started with the rebuildable stocks. The transmission is from a XX or XXT, it's hard to tell without reading the ratio on the side of the case. If it says 2.19 it's from the buggy and if it's 2.61 it's from the truck. Cool stuff, especially the hydra drive on the slipper.
The buggy is a Team Losi XX-CR. It is not a BK1. This buggy dates back to when Kinwald switched from Associated to Losi. After their JRX-pro buggy came the XX series and then the XXX series. I would say this buggy is from around 1994ish.
Had one, it was pretty good. It didn't like the rough sections too much though. The hydra-drive was nice. The improvements they made from the XX series to the XXX series were incredible.
There is no conversions for it. The differences between the XX and the XXX are great. It would be a cool kit to have on the shelf though, it's a great piece of r/c history. Parts may also be very hard (if possible) to find.