I think it’s something that bugged me since Gmod tower, The tommy gun and the double barrel with their wooden finish looks too… old compared to the other futuristic weapons;
My suggestion is remaking a Futuristic design for the tommy gun and the double barrel (maybe the base and silenced pistol too?) and keeping the actual models for SDNL, It also won’t looks like a “basic recycling of one gameworld item to another” to give the feeling of variety since you were meant to use those weapons in SDNL too anyway