OK I'm going to tell you guys what the Federal Fish and Wildlife enforcement office in Anchorage told me about the reusing of sealskin products.
They stated to me that as long as the sealskin was used in the making of the coat before the enactment of the Marine Mammal Protection Act, 1972 I believe, the coat can be used, sold, bartered, etc as long as it stays a coat. If the fur is salvaged or turned into another product, ie rests or tabs, it is NOT legal, especially if it is sold or bartered. This is the reason that Ed at Ak Bowhunting quit selling rests and material. It isn't worth the chance to get an over zealous Fed F&W interested in what you are doing.
One guy in Fairbanks got a nice 12,000 dollar fine for just the same repurposing issue. Take it for what it is worth, I know some guys have done it, but it is a gamble and I know at least one guy that monitors websites just like this for violations. Best of luck.