Hey, here's a couple pics of the rear mounts on mine.
The bolt is integrated into the top itself & uses a 'knobbed' nut through brackets mounted to the edge of the body & a plastic washer. I've never had it off, & don't really intend to, but it looks like you just spread the top a bit to clear the bolts & then it lifts off.
The seal looks like a pretty common crimp mount type, it clips over the lip of the tub & has a tube-like strip on the side. I've seen similar seals/weatherstrip in Napa catalogs, so it should be easy enough to get.
Also, there's a phone number for FleetAir on a sticker on mine... I've yet to call & see if it's still a current #, or if parts are available, but here it is anyhow: 423-569-6965
hth
Fuzz
ps: sry for crappy pics, my camera sucks.
