Seat advice - please pass the popcorn

[bigcheese]

As I continue to attack the pile of 'stuff' in my warehouse, I came across this pair of early seats. I purchased them about 10 years ago to replace seats in my '67 while the originals were off to Tony for recovering in Pepita and while Damon had the car.
Damon hasn't got the car yet, but soon. And Tony didn't get the original seats. Not yet.
So these sat in the box as shipped to me, unopened, full of popcorn, for about 10 years.
From the pix, please advise of vintage, I'm guessing '67 or '68.
The popcorn peels fairly easily from the smooth areas, kind of like peeling a thin film off a solid surface. But the basket weave surface is considerably tougher. I tried a cotton towel, and a little Wurth citrus cleaner, and it seemed to work reasonably well. But i want to be careful not to abrade the basket weave.
The seats are in great shape otherwise, no splits or rips, but the hinge chrome is a bit rusted.
So, a little help please on dating my seats, and advice on getting rid of the popcorn.
Thank you EarlyS!
Hank





Peeling from the smooth vinyl