I too found that picture of the one in the Canadian Bushplane museum, I think on theirs the lower ends of the steel uprights have rusted away while the one that’s just been found is the other way round with just the lower part remaining. Could be an opportunity for the museum to acquire some more parts. 

I couldn’t stop wondering about that substantial steel fitting so I now think Its not a Bellenca but a Buhl CA-6, in the picture attached you can see someone standing on where the treadplate would be with the strut (only the lower stub end is left) going up to the upper wing attachment point. 

There were not many of them built so identifying which one should be fairly easy. 

  https://commons.wikimedia.org/wiki/File:Buhl_CA-6_Special_NR9628_Spokan…

I think the last flyable aircraft powered by Hercules engines is the preserved Nord Noratlas F-AZVM, I sincerely hope they are able to keep it airworthy. 

I do wonder if it is actually part of a main undercarriage leg, in the first image is that a steel brake drum liner inside the remains of the mag alloy wheel. It also has fittings for attaching a mudguard, spat or fairing so potentially/maybe a fixed gear type.   

Superb programme as you say, really gave an insight into the difficulties they had to overcome. 

DH you are correct with the 504, in fact it even had an universal mounting to make life easier, and many other Rotary powered products of that time came with Gnome, Le Rhone, Clerget, Bentley engines.

I was actually just reinforcing the fact that a choice of engine dates from way before the F16. The OP’s question was ‘so am I correct in thinking the F16 is the first military aircraft to have that option?’. 

Ooops, should be David Morris, and its a brilliant book about the incredible conservation of an unbelievably unmolested survivor.  

Not seen one anything like that, some sort of heat guard or more likely a shield that unfolded to protect the pilots eyes from the glare of the flare on a high winged aircraft. 

There was an old thread on this forum titled ‘Holt Flares on Biplanes’. I cannot find it now using the Key search function but it comes up on a google search using that title. 

This doesn’t answer your question though, as well as turrets and cars Frazer Nash made the radar scanners for the Airborne Interception kit fitted to Mosquito and Beaufighter night fighters.