I have one of the flanged Polycase gizmos. I don't exactly know which model it is, but I could find out. The overall is about 2" W x 1-1/8" tall x 3" L and 3.5" between the bolt holes.
The lid will snap and stay on without using the 4 screws.
It's the BT series for sure. Look at the drawing: https://www.electro-tech-online.com/custompdfs/2012/03/14531129045666516PDF.pdf The upper left two drawings show lots of marks around the lid area, These snap it together. Remember you can get these with and without the bottom feet. If only you know: you can cut off the screws for the top and glue them in place just to make it look nicer.
I accidentally drilled the top of an aluminum box for feet, so I just countersunk and put screws that did nothing in them.
I can't tell on the LP drawing. You could call and ask.