I've got a couple CR250/500 carbs, I think at least one of them is a 38mm but I don't know much about carbs as far as them being an airstriker/PJ/PKW. I could probably loan you something for test purposes. If it worked out, then you could buy one ( I wouldn't want to sell any of mine )....if not you'd just be out a little shipping. If it's something you're interested in, let me know and I can get pictures and measure them.