Trading arcades for pinballs is EXTREMELY tough. A lot of pinball guys/gals aren't into arcades, and vice versa.
I would recommend posting them for sale on here, on FB, klov, and CL. Add into the listings that you are interested in an option to trade as well. If you just list as "trade only," it will either sit for a very long time...or people will constantly ask what you will sell them for outright.