Being Canadian I can't really speak much about US laws but it is available in Canada. If there is an import ban then getting seal fur will be an issue. I buy from Thornes which is located in Alberta and they have a good selection of dubbing including seal, both natural and synthetic. They have free shipping anywhere but if they can't export it to you then that is a problem. I recommend maybe sending them an email and seeing if they can send it to you.
Here is a link directly to the seal fur, usually I find if a site can't ship based on a ban then they say no shipping outside of country or something but maybe they just don't have that on there.
Thornes Manufacturing and Sales