70 duster bucket seats

I’d read last year that no one was making new high back bucket seat foam for the 70 Duster as it was one year unique.
My Duster is a 71 but what the hey I’ll use the 70 seats n foam outa a 70 Demon I found.
I figured 70 n up high back buckets were all the same. But last year none available
So I get a new Classic Industries catalog n now there’s a listing for 70-72 foam
Anyone know the real differences on 70 n up seat foam ?