I was going to (and hopefully still will some day) build or restore a Chenowyth FAV. I comprised a huge amount of info, including what limited TM's, etc there were (are). The VAST majority were painted flat black. The only standard for FAV's were no two were the same. So, within certain parameters, anything goes. There are still a few in actual use, but those belong to pretty "quiet" units...you won't read about in the paper.
As far as radios, some had PRC77's mounted on MT2060's. Some had Rt524/246's. A goodly amount used whatever handheld radio the passenger was using at the time.
Yeah, the biggest mistake (for want of a better word) made was overloading them. It defeated the very purpose they were designed to be used for. The key word here being FAST.
I chased down a handful of original frames in various degrees of completion. A couple were/are in the San Diego area, but the owners of those want original Government price! There turned out to be two of them, within about 15 miles of me, here in Idaho. They were radio controled units, and were pretty well stripped. The guy that actually owned them died and no one knows what the current status is.
Keep me posted, I have a really soft spot in my ice cold black heart fro an FAV.