Email me with your address, and I will send you six HUP helicopters free of charge. I got them a number of years back from the Kokoda Trail shop on Shapeways. They are 3D printed. They were advertised as 1/700 scale, but when they showed up, they were massively overscaled, to the point of being about twice the size they were supposed to be. Helicopter lengths are usually stated with blade length included. The designer mistook that figure for fuselage length alone. That puts them at effectively 1/350 scale. They are of no use to me, therefore. I would be delighted to send them to a good home.
The designer ultimately yanked them from his shop due to the resulting complaints, so they're no longer available. A quick search for Shapeways HUP helicopters turned up no one else producing them in 1/350 scale either, though SNAFU Store makes them in 1/400. Click the drop down arrow next to scale to see the 1/400 offering:
Shapeways 3D printed service has a number of aircraft from the era you are after, and from a number of different shops. SNAFU Store alone makes quite a few from the time period, and their quality is known to be good. Other shops also make items, but I would not be able to comment on their quality. For example, here are your Furies:
I have never used this designer's products, nor gotten a review of them, so I can't say how good/bad they might be.
Shapeways' site is difficult to search. The best way to approach it is to google the specific thing you're after, then add the Shapeways word to your search terms. For example, a "Shapeways 1/350 Savage" search got me this page:
Which found me these specific SNAFU Store products:
Alternately--if you have the time and desire--you can simply scroll through every single offering by any shop that you find which offers a product range of that category. SNAFU Store alone has about 28 pages of stuff, in multiple scales. Very time consuming, but it could pay off in you finding much of what you want.
Good luck. Email me if any interest in those HUPs. Thanks.