Carb from a Husqvarna 50. Put one on my p-26, works great. The different fuel inlet position turned out not to be an issue. You will have to swap out the old throttle arm from your present carb on to the one from the Husqvarna.
The wa carb from the Husqvarna 50 has no integral choke, you can use the old choke with no mods. The Husqvarna 51 and 55 changed to the integral choke.