My 2 cents: Rebuild 6 (or so) boxcoaches (the ones that are in the best condition)and equip them with center benches ala D&S, but no windows, and use them instead of the rider gondolas. The customer gets an open air experience with some shelter in case of bad weather. This would free the gons (which are probably in good shape) for freight specials as open air car for the die hard railfans.
Of course, this doesn't need to happen this season, but I think it would cost more manpower than $, so it could as well be a Friends project.
Boris