To paint I took the parts to be painted off the machine then removed all chrome strips, logos, and rear identification plate. The parts were scrubbed with stiff brush and various cleaners including Scrubbing Bubbles and Simple Green. I then painted two medium coats of Rust-Oleum Hammered Verde Green over top of the original finish. The results look wrinkled, not hammered.

I've owned several SG-1's and just acquired my first SG-3, so some impressions on compare and contrast:

First impression was that the SG-3 had been cheapened, but second take is that it has been simplified. Gone are the over-the-top spring-loaded key tops.  But were they necessary?  I don't notice any discomfort typing without them.  The external appearance of the machine is of course grossly simplified: from crinkle to smooth, from appurtenances to smooth, from knobby to smooth... etc.  One cheapening though which seems to be entirely cheapening with no redeeming design value: the paper rest has gone from something which looks like it moonlights as a slide rule to a stubby thing with sloppy tolerances in the slide. I did not like the grommet and post method of attaching the top at first: it's not something you can just flip open, you have to stand up and pull it off the typewriter. If there are issues with the ribbon this can become annoying -- as received it was not reversing but after a new ribbon with the path right and the rivets in the right places it seems to be working fine, and with lack of need to open the machine annoyance fades.

The decision between them seems to be mainly a matter of decor -- though of course all machines are individuals - but I can say that after initial skepticism i would admit the SG-3 as a true and worthy successor to the SG-1, or at least the one I found which was still manufactured in Western Germany. 

Messed up one link:

   Hello, and thank you for allowing me in. I acquired my 1957 OLYMPIA SG-1 on March 5th of this year, from a nearby seller who had it listed on letgo.com. This is what he responded to my inquiry with: 
     "Grandma put in her garage 30 yrs ago, she was using it, it has been sitting all this time. I'm not interested in working on it, just want to off load it."
     After some cleaning a new ribbon was installed 'Bernhard' came back to life! The OLYMPIA sg-1 is everything that I thought it would be after I had researched this particular model of OLYMPIA. The paper rest was cracked on its lower left side, and I used some Loc-Tite Professional Grade Super Glue which unfortunately has only worked as temporary fix, as I just discovered that the same crack is there once again. I am now thinking of making two matching plates, using one to reinforce the crack, and the other to strengthen the opposite side of the paper rest. How to attach those plates remains up in the air at this time.
   

Need help removing the platter from an SG-1. A fellow forum member here gave me some simple instructions but I've had no success and I don't want to break anything.