Well, THAT was an interesting research project. Don't know if you started with a Google search before you came here, but I learned all sorts of new words like Woonplaats and Weersomstandigheid while looking for info. Seems they are German (Lanz) manufacture with JD engines, and they win a lot of pulls in the 2500kg class with them in the Netherlands. The best source of opinion I've found so far is searching the JD forum at Yesterday's Tractors.
I think I've determined by looking at Germanic languaged parts .pdf's that it is a 202 cu in 4 cyl diesel with a bore & stroke of 98 x 110mm or about 3.858 x 4.33 in. I've seen 'sploded diagrams of the hydraulic pumps, but not been able to decifer any flow data. Perhaps others could brave the great gutteral world of our Northern European bretherenand bring back more information.
Pre Teen Homeschooler Humor: "What Continental Nationality are you if you're at Octoberfest drinking gallons of beer?.......You're a' Peein!!"
This was the best I could do for a picture. It's actually a 510.