both of your engines are made by OS

the engine in the supersport looks like a 40-46 size and a little older since the needle valve in mounted in the carb, most of the newer models now have remote needle valve locations, look on the side of the engine case there is usually a logo which helps ID a engine type as well if its a LA version it drops the value a bit since it would be a bushed engine rather than having berings a somewhat important distinction for value judgments.

the engine in the extra is a little newer the cooling fins have a rounder shape to them which means its a fx (slightly older) but still a new generation engine.

if you pull the cowl off the extra it will help, hard to tell the size of it all covered up, the older engine could get between 50-75$ if it was cleaned up a bit, the newer one mabee a bit more depending on its size, larger means more worth.

too bad your not into the hobby you have a steady trainer to sport line up