Hi fella,
I think access as a whole is very good. However, as a walker, you tend not to notice the odd step or two here and there which may cause problems. I'm sure he's been told before access somewhere isn't a problem only to find after it is. So, please don't take my word for it.
All the kitcar owners / groups are around in fields so access to these should be ok. The only thing I would say is sometimes I've been and the grass has been really long. Inside they are hangers so again should be ok. There are bits of gravel tracks but from memory, a lot is tarmac too. I'm more inclined to say yes.
UPDATE.. I've just called them and they say yes, not a problem. They even have disabled parking for visitors so you might get to park closer too :-)
Hope this helps,
Steve