[DRG]

You need to use the "SP fix" button in SHPEDit to tell the SHP code where on the hull you want the turret to be and where on the turret the pivot point is.

The white bits are usually a light grey that is almost the same brightness as the normal pink transparent and with practice, you get to recognize them but windows paint is a painfully basic editor for building Icons and if you are serious about building some you need to use something better.