I'm a big D50 and "Scampage" (Scamp / Rampage) Fan, and own a few of each.
I can kinda figure out the reason for the Scampage, an extremely limited market. But the D50 filled the shoes of a bigger brother easily. They had a 1/2 Ton Payload Rating (sometimes More), could haul well more than that. They got awesome gas mileage too.