RE: OS FP/LA -.15 Carb
I will check for you tonight but the OS 15 CVA carb is about as good as you can get. the next inline is the Magnum 15 carb. I think they both will fit but have to check tonight after work. The carb is 40 dollars though and its almost better to just buy a whole new LA 15 engine and try to sell that one if you can.
another option is to buy a used LA 10-15 FP 10-15 on here or the other place.
swap meets are also good.