sources for drop-down bed for class C

[Pargin4]

Hello,
I'm hoping to get information on a source for drop-down mechanisms for use in a class C. We waste time every now and then watching class C renovations just to get ideas. Recently, we've been watching BBandtheRV, which is a young couple with what looks to be an early-mid 70's Dodge platform class C. It has a drop-down bed in the over-cab area. Because it's up there, it only has to drop a couple feet if that.
We have the whole mattress-sewn-to-plywood that we can flip up out of the way when driving, but we never do. We would love to just have a drop-down like this. It's fairly easy to find them for class A's, but they look like they drop way farther than we could use. Does anyone have a source for these old class C drop-downs? I'm to the point that I might buy a junkyard one for a class A and shorten the arms.
thanks,
Pat

[Oz]

Yep, junkyards and RVs being parted out are the only sources.

[Pargin4]

Found my donor! 1979 Pace on a Dodge chassis. Only $15 for all the hardware and the bed itself, which i figure will make a good pattern. Real shame to see such a cool old RV ransacked in a pull-a-part, but what a score!