I have seen both the Distinctive Industries (DI) and PUI deluxe seat covers. I actually installed a set of DI seat covers on my 68 deluxe sets. They were very soft and pliable - easy to install, but the vinyl was definitely 'soft' compared to my original covers (you could scratch the vinyl with your fingernail). From what I remember the stitching on the 'insert' part of the seat was not correct. They were also a little on the puffy side. It also took a lot of exchanging before I got a set that looked nice enough to install. However, that was some time ago and maybe they have changed.
Not being happy with the DI covers, I bought a set of PUI ones. The PUI covers were very nice looking (don't remember if the stitching was correct). The vinyl seemed very heavy duty and firm, but it looked like they would be tough to stretch and fit properly. I sent them back.
Like I said, I ended up getting covers made by CARS, but only because I decided to go with houndstooth and PUI did not have them available. They are very, very nice quality - hand made per order. The vinyl weight and texture seems just right. I did have to exchange some pieces of the set several times to get ones that were perfect, but it was worth it in the end. I'm not sure if CARS would make a 'plain' set of deluxe covers, but you could give them a try.
Sorry to ramble on here, but there always seems to be a story behind everything I have done to this car.
