From downloaded part as I have no software for opening solid works drawing files. From the part file it is made from 1/4 inch thick material. If these are steel parts (or stainless) laser cutting could be a great option to make many of these, or even a few. With a fiber optic laser this would be a good way to make brass or aluminum parts like this as well. This would be of course, dependent on laser cutting providers being in your area.
For making large quantities punching with a progressives punch and die would be worth looking into. Machining parts would be slow. To beat laser cut price would be only with large quantities punched.