Help identifying Bertoia 420 side chair  

I've combed through all the threads on the 420 side chair ID'ing, and I've referred to the Bertoia guide on id'ing an authentic, but I'm not quite sure mine is or not or the approximate era. Would love opinions. It has no labels or markings that I can see.

It's got three gauges of wire (the base, the wire surrounding the seat, and the interior wire), and I've seen the type of brackets that are used to attach the base to the seat referred to as authentic.

Mine doesn't have the waterfall front edge though - seat wires are welded to the top of the wire that goes around the seat, not the underside.

Obviously, it's in rough shape but I'm hoping to be able to clean it up myself (will be looking for guidance on that as well...)

Thanks for your help!
<img class="wpforoimg" src=" http://d1t1u890k7d3ys.cloudfront.net/cdn/farfuture/e_I05_cLXcLnI_6Zr3ZHpE