Last time I checked the answer was no. And that includes any products made from seals. Check under "furs".
https://www.fws.gov/le/tips-for-travelers-species-list.html
Thanks for the link. That doesn't sound too promising for bringing hides back.
On a slightly different note, the language of that USFWS page makes me wonder if products purchased out-of-country and made from seal skins might be allowed into the US? USFWS specifically states the cat species listed as 'endangered' and notes that items made from their fur may not be imported, however, regarding seals, polar bears, and sea otters, it merely says the
furs are prohibited.
"
Furs: Most of the world's wild cats, including tigers and such spotted species as jaguar, leopard, ocelot, margay, and leopard cat, are endangered. You cannot import skins or items made from, or trimmed with, the fur of these animals. Furs from seals, polar bears, and sea otters are also prohibited."
Now, I'm pretty sure you're not allowed to import products made from polar bears into the US, but as I understand it, polar bears are listed as 'threatened' whereas seals are not. Standard Velocity mentioned that Newfoundland having a lot of sealskin products for sale, so at the very least if it weren't possible to bring back the furs from the actual seals you shot, perhaps you could purchase and bring back local sealskin products? Maybe I'm reading way too deeply into the USFWS's wording!!