Marty: Pays to visit the pawn shops.
These screws are all mixed up on reassembly. Probably the rear screw was meant to be a left or right and the left or right screws are also on the wrong side. The left screw will have a straigt cut across the tip. The right screw will have no marking. The rear screw "should" have a + cut on the tip if all three screws are the same length. If one screw is obviously longer than the rest, that is the rear screw. If you remove them, and if they are the originals, for sure you will find the left screw and be able to place it in the proper hole and it should index with the slot stopping in line with the long axis of the gun, as they all should. (Left means under the left barrel btw)
Here is the left screw mark. Ignore the comment on the + mark in this picture. I need to fix that. Still learning. + was a mark used to identify the rear screw when all three were of the same length. By default, the screw with no mark is the right screw, when all are the same length. Replacement screws, to my knowledge, are not marked.
Have a very close look at this engraved area on the underside. That is the location for the safety slide. If it was removed welded and refinished there may be evidence of that on the underside. Or..... wait for the letter
