Forgive me if I'm wrong Pete as I've never been privy to talks with councils/clubs.
I recon that if a club were to approach their council and advise them that they had some interest from wheelchair bound people to use the facility, that a council would almost help fund/build a stand that would be suitable.
Every effort is made usually to make most things these days accessible to the disabled so I'd recon a council would want to help.
I've only ever been to one club (Brendale QLD) that has made a effort to make their track accessible to those in wheel chairs with a ramp up to the stand and a layout that enables people in chairs to get about the place.
So just think if something happened to you any of us tomorrow and you found yourself in a chair. The dificulties that you would face trying to continue with the R/C sport.
There was an interesting discussion on starting grid about the same thing. It mainly centred around tracks that qualify to host what they call regional races in the US (bit like our State Titles I guess). Well there just weren't to many that came up to spec as they are suppose to have access for the disabled.