It's almost impossible to get rid of all the rust on something like this but I try to remove as much of the rust as I can.
I thought you would cover the rust, but maybe not.
If the parts will fit in the cabinet, then I sandblast them.
If not, then I go after them with a 36 grit disc on my air grinder.
I've also had good results from using Eastwood's Oxysolve to chemically desolve rust if it isn't to heavily rusted.