This might help for what you are thinking about although it is not cheap and they don't provide much more than basic information:
https://www.summitracing.com/parts/q...2/applications
No doubt there would still be a lot of work left to do to get everything to play nicely, including figuring out an internal concentric hydraulic clutch release system since this bellhousing looks like it doesn't have a place for a regular release fork. Custom clutch disc too. But it might at least do the main work of getting the engine and trans bolted together, as it is meant to mate an Audi 5-cylinder (same bellhousing pattern as the D24) up to a variety of old school style 4sp transmissions that might be similar to yours.
It's probably meant for drag racers using turbo Audi 5cyl gas engines which sometimes make 1000hp or more so ought to stand up to an 80hp diesel.
Otherwise the adapter options might be limited unless you can make your own. There aren't many companies selling parts to bolt these engines up to other applications. But one other option out there for getting a D24 bolted up in a 4x4 application would be to get a complete ZF 4HP22 transmission with transfer case out of an old Range Rover and then bolt on a bellhousing and torque converter from a Volvo 740 TD ZF auto, which is the same basic transmission. You can put the Volvo TD valve body in too to get diesel shift points. Then you have the engine, trans, and t-case figured out and just need to modify drivelines to bolt up. But it also means changing to an automatic transmission and you might prefer to keep your standard. For what it's worth the ZF is quite a nice automatic, smooth shifting and efficient with an overdrive gear and lockup torque converter. Anyway just one more idea in case it is useful. There are a couple members on here who have done it.
If the engine is painted blue that might mean it is a rebuild done by a guy named Chris Bogue who apparently did a big business in D24 rebuilds in the Portland area in the '90s or '00s. He would paint the blocks a kind of turquoise blue. I had a car once that had one of his engines and it was a great runner, had a metal headgasket even, he was known for doing a good job and being an expert on these. So if your motor was reworked by him, as many of them around the PNW were, that would be good news!