Bridgeports and clones have a small boss on right side of the quill housing, 1/4" Ø and crossed tapped 1/4"-20. It's probably for an eyeshield or some nonsense. Oh thank you OSHA, our workplaces are so much safer...
I like it better as a mount for mag-base spray coolant. A steel plate is welded to a simple bent rod, about 15°.
An angled face provides seat for the housing's 1/4" cap screw. The angle holds with just finger-tight pressure from the screw.
You'd want to fiddle with the design; I was tween welding plate horizontal as shown vertically, mainly about access to needle-valve. There is about equal clearance either way, though version II will lengthen rod farther back. As soon as I find my extra coolant line snap fittings.