Something else to consider;
If the concluded intent is to purchase and place as many suitable wheelchairs at as many Cemetaries as possible, how much would they actually be used ? As uplifting as the original story was, don't most people who are immobilized (or their caregivers) pretty much always make sure the wheelchair travels with the person that needs it ? Last thing I am trying to do by asking this question is to appear to be criticizing anyone, especially the disabled Vet. But, did he (or his caregiver) "forget" to bring the wheelchair ?
If most, or even the vast majority of disabled people bring their own wheelchairs to Cemetary visits, I'm concerned that a (S/H) "Sponsored" chair may sit and gather dust 95% of the time. Of course, the 5% of the time in use would make it worthwhile.
Or, maybe contact staff local to a given Cemetary and ask them for a list of prioritized "needed items". May be that there are other things besides chairs that are consistently higher on the list. Not sure an administrator is the right person/persons to talk to.