Sig still makes the little bugger for about $125 USD.
https://sigmfg.com/collections/sig-kits/products/sig-astro-hog-kit
YS-120 & Saito 150!!! Your are power hungry my friend! Floats are quickly becoming my new pastime. Nothing beats a calm day of float flying. Sounds like a 20cc gas engine would make it pretty fun.
No Sportster.
I'm going to look through all the kits and decide what to do with them. I may end up with more. The grandson said if they don't sell or they need to just give it away they'll call me. If anything, there is some good balsa.
If anyone was looking for a plan to scratch build... he had forty or so. Mostly under 90" WS models. happy to retrieve them and send them in the mail.