Around the late 70s/early 80s Falcon wasn't in a great place and produced multiple very similar models based on the same imported frame which didn't appear in catalogues. The frame is the same as the gold version used on the model 62 Panther and many others but from the kit on it (the 12 speed)...
You've done a hell of a job on that chrome, must have taken a lot of work.
The outer chainwheel is rotated clockwise by 1 position too far. The pin that projects from it should be located behind the crank as it's there to help stop the chain jamming between the crank and spider.
I found a Chinese copy for one of my bikes - black buttons and (obviously) no Elite branding on the bracket but otherwise very similar. There's a used yellow button Ciussi on Ebay UK at the moment than that looks to be in good nick.
The Ciussi Inox stainless cage has red buttons, the yellow buttons were on the original alloy Ciussi. The Elite 3c cage (also called the Ciussi 'Black' by the company) looks very much like the original and has yellow buttons too but is only available anodized black.
Originally Oscar Egg's company, produced all sort of kit (mainly rear mechs) under the Super Champion branding. Eventually owned by Wolber and then passed on (complete with the remains of that company) to Hutchinson.
From the way it follows the line of the joint I'd put money on it being cracked braze filler though there's a small chance that it's just the paint if the joint wasn't cleaned properly before the frame was painted. Not difficult to fix.
A standard outer cable slides through the tube on my FCK9. Unlike the dural frames, the seat post is 23mm. Although stamped VITUS, I believe it's actually a Stronglight Delta post. I maybe picky about it, but whosoever made it, it isn't great - before I corrected it, the 'aero' section on mine...
I used to ride 177.5 then dropped to 175 when I started riding again because at the time there weren't any longer cranks immediately available. My new build has a set of 180 waiting to be mounted once the frame has been refinished.