Thanks for the responses, appreciate them. Yes, I think I will get the others to play around here, convince them it's better for our members and for them.
Part of the problem is the previous head admin died very suddenly, taking with him all the vB and domain info. IB have very generously allowed us to continue using the vB4 version we have installed, but won't allow us access to any upgrades or security patches. I wasn't very favourably disposed towards IB or vB4 anyway, but I find their unwillingness to even countenance anything at all is, well, indicative. But it does mean we effectively have no working vB licence. Which is very worrying, particularly with IB's track record.