If you can't find the seals in a kit you can find most any seal at a "bearing" house. It is just a std seal that was fitted to the carb. The seal may even have numbers on it for an easy match. If no numbers take a caliper along you'll need OD ~ ID & sometimes length. I use Monarch Bearing for seals and bearing needs and have found every one I have looked for, even on 50+year old machinery, engines and especially transmissions.
Dave Neptune