Interesting & timely post for me as I've been looking for a press cover. I presently use a pillow case to cover the press. That works fine for dust but rust can sneak up on you no matter where you live. I keep my presses in the house where it's air conditioned.
I've been trying to contact the company that makes the "Sack Ups" firearm covers to inquire if they would make a larger size that would cover a press for longer term storage. I load about a thousand rounds at a time then won't load for a while. Has to do with work getting in the way of free time. I sent the Sack UP company an email on the subject but got no reply. I forgot about it until I saw your post.
The Sack Ups are a knit "tube sock" material impregnated with silicone to inhibit rust. Presently the Sack Ups company sells scraps if their material for gun cleaning in a package of 3. They are shorter versions of their full length rifle/shotgun covers in a "tube sock" style. I've been purchasing those as they are large enough to cover the head and base area with the press in the down position. I don't think the silicone will effect the paint or decal on the press. I place one of those over the head & base (press collapsed) then place a pillow case over that. I tend to steer clear of anything plastic for a cover as moisture can condense inside of the bag. It's always sad to see one of these little works of art that has been neglected and rusted up.
Diesel