Mystery Safety

[GaryS]

I got this in with a lot of 3rd Gen parts. At first I thought it was a single side 39xx safety, but it's not quite the same. First, the finish is glossy. Second, there is no hole for the retention spring and plunger. There is a groove instead.

Pictures are attached below.

Is this a 1st or 2nd Generation safety? Or something else?

Once I know what it is, I plan to put it up for sale here since I don't have any use for it.

Thanks.

[jsbethel]

Model 52 is my guess.

[tom 45]

my 39-2 looked a lot like that.