For these I used Rustoleum Oil Based Hammered Finish, it's direct to metal, so no primer needed. I just chemically stripped it with a citrus stripper, and then ALOT of time between my wire wheel and my sand blaster so I got all the old finish off.
As a general rule, I stay away from water based paints or spray paints, as the finish isn't as thick and it can get damaged to easily. So I stick with oil based paint, and if I'm using a hammered finish, I use a brush to apply it and dab it on to increase the hammered look.
As an extra measure of protection, I use a clear coat. I really like the 2K clear with the added harder for larger items. I say that because 2K clear is little pricey, and once the harder is added, it has a very short shelf life. So if I'm doing small stuff, I use the Majic tractor and implement clear coat from tractor supply out of my HVLP spray gun. Just so that way I don't waste product.
I used to paint commercial aircraft in my younger years, so my methods are all about durability for the most part. Which seems fitting for a bench vise project(s).