If the rest of the car is in good shape you might have something here if the price is right. Since it hasn't had any maintiance in 50k miles the entire car will be needy.
The engine may be salvageable, figure at least yanking the heads and tanking them would get rid of the sludge in the valve train. Repair any damage you find of course. Then drop the pan and clean it out, with a few short oil changes the engine may actualy be ok.
The simple fact that it went 50k miles on the oil is amazing in itself, the M119 seems to be about impossible to kill!
