As you may recall I ordered a thumb safety for right around $20 shipped. It's ambidextrous, and I was curious as to what kind it was.
It turns out it's an Auto Orndance ambi with wide paddles.
It looks like it's cast, not MIM, and it's strong. It is held together with a screw. I'd recommend a bit of proper color Loc Tite.
A few swipes later and it was fitted. I like how they did this - even without the right side installed, the primary safety will fully support the grip safety.
As you can see, the safety pin goes partially through the left side hole.
The right side paddle has a stunted stud like pin made up mainly of a groove.
After I had fitted the safety, I fully installed it and tightened the screw. It would barely move with the right side installed. I worked with it for a bit and then gave up. It would work fine with the screw loosened just a bit, but not when tightened down.
After I took a break, I put it on my Charles Daly. It worked fine!
I do not know if the frame was a bit thinner than on my RIA (the Charles Daly is an early Armscor model, just over serial number CD1000) or if the tolerances are a bit larger in the CD. The two theories I was working from were 1) The safety clamped too hard to the sides of the frame and 2) the groove's ears would spread out when things were tightened. I've not been able to confirm either of these theories though, so it remains somewhat of a mystery. At any rate, since it fit the CD, that's what I put it on.
The safety itself looked almost like they just sent it fresh from the cast - rough edges and flash. If you want it to look professional, you will have to clean it up. I used 1000 grit sandpaper to make it shine.
Regardless of whether it's finished when sent, it does feel like a quality part. Maybe the additional $50 other manufacturers charge is for finish? Regardless, with no grips to support it, I put full thumb pressure on it to try to break it. Then I flipped it on and off 100 times or so, and it didn't loosen up. I believe that, by being held together with a screw and the tongue-in-groove setup being supported by the frame, it has an inherent strength other ambi safeties do not.
I would very much like to see someone like King's or Kimber take up this idea. If they combined this idea with their hammer pin retaining system, I believe lefties would finally have an excellent, extremely strong thumb safety which they could count on not to break. It would likely be way more durable than anything we have today.
I give it a 10 for quality, 5 for finish and a 7 for execution, but only because it wouldn't fit the RIA well, and I know the RIA to be in spec.
If you're looking for a good ambi safety and don't mind finishing it yourself, I'd recommend it highly due to the price. However, if you don't want to take the chance of it not fitting and don't want to be out $16.30 plus shipping (though I believe Numrich would let you return it), I'd recommend a King, Brown's or Kimber instead.