Ran across this in my surfing:
http://cgi.ebay.com/ebaymotors/87-88-Thunderbird-Turbocoupe-Right-Power-Seat-Unit_W0QQcmdZViewItemQQcategoryZ33701QQihZ003QQitemZ130106355436QQrdZ1
An easy way to upgrade your seat to power if you wish...my advice is to do what I did: paint the entire frame before you install it (I did mine in black) to keep rust away.