Seat upholstery problems. Please help!

[Darrell67]

Here is my story.
I got a 67 lwb c 20 stepside that i ve been restoring to original(for the past 5 years.).Everything is finished except the seat. Mine was in bad shape,(all ripped and broken springs), so I found a donor out of a 70 GMC. After looking for a long time,I couldn't find an original seat upholstery with the proper patern. I live in Canada and I found a supplier in Ontario who deals with PUI interiors out of Kentucky. They said they didn't manufacture one for the 67 but they were interested in doing so . So I sent them my covers and they set up their equipment and duplicated mine in teal green, the original color. There is only one problem, when it got here it was 3 inches too short. (56 inches.) Then I sent it back and waited all summer and when it finally arrived it was still too short. After calling the company they said they still had the old one and it measured 56 inches. My questions are, 1- Could the old one have shrunk or did they screw up and just wont admit it? 2- A 67 cover should fit on a 70 seat, right? 3- Did anybody ever deal with PUI? (are they a reputable company?) 4- Does anybody else manufacture this cover?
This cover is now in their catalogue under new products(so I am told) but I cant see that they sold any at that size!
Thank you for listening to me and any information or comment would be greatly appreciated!
THANKS!!!