These were known as Spenser Panels, for anyone who has bought from Spenser.
I have not used the panels, so I can not comment, however there are a few people in the club who have. In fact the red truck in the pics is a club member. It is as nice as it looks. As too fit/finish and difficulty of install...dunno how it went. I believe some of the aftermarket panels available are resellers of his panels.
He is supposed to be working on the jigs for 60 series panels now.
The rear sill is what I need. He's faxing me the install directions and pix, I won't go to work to scope the fax til Monday. His price is waaay better than the ~300 ccot wants. I'd rather use 3/16 2x2 and fab it by hand than shell out that knida cash...It's all just about convenience since I gots plasma and mig in the shop...