I had quite a few of these made up several years ago, I thought I would see if anyone here wanted any. 
The dimensions are as follows: .625"L x .500"W x .275"H
The dovetail is 1/2"x60deg and a depth of .090". You can see that the internal corner of the dovetail has a small radius in it. 
I only spent a couple minutes polishing this one with 400 grit to show what they would look like. The rest are NOT polished, and they are NOT drilled and tapped as you can see. 
$15 each + $5 Shipping CONUS

PM me for address if interested.