I also say stick to your guns! Sometimes, well lots of time, people try and take advantage of someone is nice and it ends up backfiring for the "nice" person who is trying to be accomodating.
Especially in the Business World, I say, stick to your policy of no checks. You have to have guidelines and safe guards. And especially because you are dealing with Other peoples things. If anything was to go wrong, it would be you who would then be responsible. Don't take the chance. The bidder knew the policy and if it wasn't acceptable to them, they shouldn't have even bidded with the expectation that you would bend the rules.
Sorry didn't see this sooner, but looks like you didn't need my advice...you got all good advice from others. I should have just written ditto to everything below!
-------------------- ~ Beth
Constipation, pain prodominent,cramps, spasms and bloat!