i just ordered seat covers for a 73 dart sport [front bench with arm rest] in the original "bright blue" [b5] vynl.
6-8 month lead time, and when you order, you own them. the only thing to discuss when you receive them is if they are the wrong color, or they are damaged somehow in shipping.
as this is not my car, and i am just a parts procurer for the owner, i research parts then make [my] recommendations. the owner has the final say as to what to purchase and what company to purchase from.
if it were my car, i would have one of the trusted local upholstery guys sew up a set of covers. it would be cheaper, faster, and look the same as his original covers.
i suggested this, but it was not to be.
it will be interesting to see if these covers come "antiqued".