Photographic proof! I searched high and low for images made with this unusual SLR, and only located a couple of fairly underexposed shots on flickr. That was it, in the entirety of the whole world for this camera. Now I know, here at this forum we don't get too fixated on the machine side of photography but given the strangeness and the rarity of this camera, I feel inclined to talk about it just a little bit. The first Firstflex 35 appeared in the mid 1950s, it looked like a severely deformed Exakta, sported a leaf shutter, and was one of the first 35mm SLRs made in Japan. In 1958 the second model came out. Looking rather more stylish and streamlined, this new model featured a sector shutter like the Exa, but crucially incorporated a then state of the art instant mirror return. The real oddity of this mechanism however was the shutter only had one instantaneous speed: 1/125. Despite these cameras being available for several years, few were made. Serial numbers suggest that perhaps as many as 3000 examples were built.
The lens features an automatic aperture, which was also a state of the art mechanism in 1958. Pentax didn't yet have one, and the Nikon F hadn't come out yet. Only a few SLRs featured semi-automatic aperture mechanism at the time, the rest relied on manual or pre-set controls.
Beyond that, there's not much to say about the thing, as it is fairly normal. It has an eye level viewfinder, a right-handed wind lever, a shutter button on top, and is generally (except for the single shutter speed) pretty typical of an early 1960's  SLR. The one frustration I experienced was with the film transport, as there is no interlock to prevent you from winding on after the cocking the shutter, you can wind on and on wasting frames without shooting anything. I lost two frames this way.
After some cleaning and minor repairs, I loaded Ektar 100 into the Firstflex, and headed out to see what would happen.
 there
there by 
Berang Berang, on Flickr
 pipes
pipes by 
Berang Berang, on Flickr
Some barrel distortion is apparent.
 dog line
dog line by 
Berang Berang, on Flickr
 pipe more
pipe more by 
Berang Berang, on Flickr
 melon remains
melon remains by 
Berang Berang, on Flickr
 rust in the sky
rust in the sky by 
Berang Berang, on Flickr
 a place
a place by 
Berang Berang, on Flickr
 another place
another place by 
Berang Berang, on Flickr
 saab
saab by 
Berang Berang, on Flickr
 face thing
face thing by 
Berang Berang, on Flickr
 bridge
bridge by 
Berang Berang, on Flickr
 names names
names names by 
Berang Berang, on Flickr
 pole
pole by 
Berang Berang, on Flickr
 Tokinon 2.8/45 boke'
Tokinon 2.8/45 boke' by 
Berang Berang, on Flickr
...just boke' - for science of course...
 Tokinon Test
Tokinon Test by 
Berang Berang, on Flickr
 cycling
cycling by 
Berang Berang, on Flickr
 Bronco and Construction.
Bronco and Construction. by 
Berang Berang, on Flickr