I surely see what you mean. I found this one on GB,
http://www.gunbroker.com/Auction/Vie...Item=305055847, and it does not have the two screws in the back. I also notice on the back of the slide, if think I am using the wrong part name here, it is stamped with the last two ser # digits. The one I examined was stamped with the last three and smaller parts with only two. The plot thickens a little. Did they fake these pistols? I have no idea why anyone would add these two screws and what purposed they served. More pics coming!