You said the engine at one point was using 2 quarts in 120 miles. Did it correct it self or is it still using that much oil? You said it was smoking and a lot of fuel was going out the back. What color was the smoke? (white, blue, or black). white is steam, blue (blue/gray) is oil, and black is fuel.
With the engine running can you see the draft tube on the rt. front side of the engine and is it smoking profusley? (bellowing smoke?) There should be a little even if the engine is running well.
The stalling condition you discribed is most likely lack of 1 of 2 things. Fuel or Electricity.
Do you have an inline filter? If so go to the filter with a glass container in hand remove the hose from the fuel tank side first and catch the fuel that flows out the filter in the glass. (note; fuel may also come out of the hose from the tank you can pinch off the hose to stop it or shove a large phillips head screwdriver inside it. Some old bolts have a cut off valve where the line gos into the tank.) Do you see any water or trash in the glass? If so you have fuel contamination in the tank. The filter is stoping up and engine quits running (starving for fuel) then you pull over let it sit and the dirt and crud fall off the filter surface inside the filter. It restarts and you drive a little further, it re-stops up only quicker this time cause the trash is still in the filter (just on the bottom). You will see fuel in the glass bowl if the in line filter is before the bowl.
It could also be a lose of electrical power, maybe from a bad connection or lack of and engine ground. You said you had some charging system issues. Did you fix them? A bad electrical connection or ground will heat up as you drive the make a worse connection and starve the engine of electricity this will inturn cause the vehicle to stall (just like it is running out of fuel). And when it cools off the connection is better and off you go till it gets hot again.
Thest are the things I would check first. Then I would move on to vapor lock, fuel percolation, or possibly stoped needle and seat in the carb.
Good luck.
