Can somone demystify Interior Trim Codes?

My 2001 Voyager van has a trim code of J7L5. Right after purchasing the van two years ago, I bought Captains chairs that clearly don't match the original cloth. Yesterday, I bought a set of 50/50 third row seats, that match the Captains chairs, but don't have headrests.

I now have two bench seats with trim code J7L5 I need to get rid of. EBay is waiving sellers fees this month, so I thought I would try to unload them on eBay. The alternative is to pay to have the township take them. I know when I put them on eBay, I will get questions about will these seats match another similar trim code. I'd like to understand the trim codes.

Also, I need to buy headrests for the 50/50 seats. The headrests from bench seats have the posts further apart, so they won't fit. It would be nice to be able to identify the fabric pattern, and get used headrests that match.

Thanks in advance.