Someone recently posted on another forum, regarding his T-bird's seat height being considerably higher after being reupholstered; his head is now above the top of the windshield. In his case, I don't think the new foam was trimmed before installing the upholstery. Over the years, foam will compress and deteriorate, thereby reducing the seat height, so you may see a considerable before/after seat height difference. Considering the cost of materials, I would leave the job to a professional who has done T-birds. 

 I would buy the video first, then decide on doing the job. A leather cover may make the job harder. Also 57's came with or without the emboss emblem on the back rest, depending on the manufacture date. The new dense foam "looks" great, but will raise the seating height. I have switched the drivers and passenger springs because the passenger side were used less. If you have a power seat look at the seat rails for excessive wear and good operation. Does anyone have any experience repairing the "waffer" part of the lower power seat motor of the Dial -o-matic seat on a 57 Bird?

When I had my 55 done years ago, I used the leather seat cover from Larry's Thunderbird, along with a whole interior kit. The local upholstery guy did the seat bottom and back first, then went thru the rest of the interior, carpet, etc. I used new foam. He stretched the seat every morning (in a heated shop). He said if you had time to do that it was the best way to get a proper fit, and worth the money for him to do it 3 or 4 times. It still looks good for fit 18 years later so he must have done something right.

My wife and I covered the seat in our 57 T'bird a few years ago and I think it came out fantastic! We had planned to take it to our local upholstery shop on Cape Cod , Ma but were informed that he was so busy (It's a one man operation) that it would be well into the fall before he could do our car.He said we could do it  if we did 2 things. 1-buy a pancake air compressor and its hose and staple gun (reasonably priced at Harbor Freight) , plus they always have coupons.  2- You must do it 0n a  90+ degree day after letting the covering sit in the hot sun for hours. If you dont do that you will not be able to stretch the material the required amount.We bought most of our supplies from Casco, i.e., upholstery package with tack strips , hog rings, etc.  Took our time on a very hot day in July, did the seat on the first day and the seat back on the second day. I stretched the fabric/vinyl while my wife fired the air staple gun.! The whole operation was pretty sweet and I cant overstate the importance of doing it on a VERY HOT day..  Good luck    RJ Palmer