I always like to isolate a problem whenever I know multiple problems may be occurring. I would fix or at least minimize the leakage, before doing the overhaul again. Eliminating the leakage may allow you to quantify the burning. I know diesels are renowned for their runability, even though mechanically weak, but 1.5 quarts/100 miles is a lot of burning for an engine that shows no other symptons (ie., hard starting, smoke trail, oil trail, etc.). In addition, there are other areas that could cause high oil consumption that you may be overlooking. Mainly, in the head (valves, seals, etc.).
My $.02 worth.
1982 240D Manual - Sold