I agree, it looks sketchy! But it looks (at least partially) manufactured. I saved it from the scrap yard and figured the frame was worth hauling it home.
I don't really have any expectations of getting this thing going with diesel, I'm sure the seals in the pump are bad.
I think I will work on changing it over to propane, it seems easier to regulate a pressurized gas than to dial in this series of valves and return lines.