AC Fins and vent ?

Hey guys hopefully you can give me a hand here. On my 1997 Prowler fifth wheel ceiling AC unit there is a bar on each end where the air comes out and on that bar 8-10 little fins you can move left or right in order to direct air. When I bought this unit last year and started touching them lightly to move them they are so brittle they just crack and fall apart in your hand.

I noticed the fins look like they just push and snap into that bar, I have tried google but I guess I have that part name wrong or something and can't find any and wondered if someone could point out a website where I could buy new fins or a whole new bar with the fins already on them ?

Here is a pic were you can see the unit in the ceiling.



Thanks