I have not looked at the Oshkosh airport map since I flew in there in my J-3 many years ago. However if there is room would it be possible to extend (!) one of the paved runway with, in effect, a grass overrun area where the older aircraft could touch down. It is just a thought and I have seen such airports which worked very well...made me feel very welcome with my no-brakes railskid equipped Taylor E-2 Cub. Even in a three wheel equipped Taylor J-2 without brakes, I hated the thought of landing on pavement...that horrible sinking feeling was potentially there ...with the thought of the wheels "locking on" to the pavement while the rest of the airplane wanted to keep on going to one side....ugh!!!
I should think another factor not mentioned (not that one can do much about it!) is the weather. We have seen "Sploshkosh" and we have seen the winds at Sun 'n Fun and these sort of things can have a great impact on the pilot/owner psyche. I have talked to pilots who since then have had some very sobering thoughts about such a trip...and am sure it did have an impact.
Perhaps for older aircraft, local clubs/groups around the country could "volunteer" to invite pilots to use their "grass runways", enroute to and from AirVenture? With some local support around the country, pilots could pick up specific "migration flyways" to follow to get to Oshkosh and Sun 'n Fun as well as certain other gatherings? Actually it could become quite competitive and thus provide more grass, parking and fuel supply offerings. Eventually fields could get approval ratings as "EAA Vintage Flyway" hospitality locations for vintage aircraft? Thus there could be as much pleasure in the "going" and "coming" as there would be in "being there"? Perhaps the Vintage Division could provide such fiels with large "VINTAGE FLYWAY" decals to be displyed at such fields?
I think it important to realise that many of the bigger and "modern" airports -being staffed with highly- trained specialist personnel and the most modern of equipment- are simply not equipped to handle vintage operations. Perhaps we should pity them, for their experience and wisdom is obviously both "narrow" and "limited".
We denigrate our past if we do not keep the vintage aircraft flying. Each such aircraft is a flying and mobile museum. How shall we understand our present and our future if we do not understand our past?