What to do with my dad's old Revel Performa F50's?

Good advice from several here. Did your dad try to modify the speakers in any way? It seems strange that there would be damage to the rubber surrounds which are usually pretty durable, and then there is the missing paint on the front of a couple of the baskets.

Hey there — so just clarify these ARE F50’s. Not the F52’s. I’ll attach a picture to the listing. 
 

He did not alter them in any way, he’s not technical at all. A local home theater business set them up and he didn’t touch them for 10 years at least. I think maybe the deterioration is because he lives by the ocean and had the windows open? Maybe that was it. I could imagine the salty air playing a factor in the deterioration. 

Very nice speakers! Here is my 2 cents worth. First I looked close at the photos on your ad and the surrounds to me do not look like they need replacing unless I am missing something.. Those cuts look like the screw drive slip when prying a speaker out if its nest, you only do that once!!!. Second, I buy and sell used speakers and one thing I have found is that they are cheap to buy and hard to sell. The market for a particular higher end brand is quite limited and the buyer is in fear of a "bad buy" due to defects and unseen alterations. Shipping of speakers that size is all but cost prohibited so your are dealing in most cases with your local market. One option find a dealer close to you that might sell them on consignment. Good luck with your sale.

Thanks mteetank. I may need to just reduce the price and cross my fingers someone will be interested in them locally. Cheers!