Can I suggest making the delivery date the day of the meeting ... Friday, April 21st? That way people won't have to drive to Hudson which, for most members, is close to the same amount of money that shipping would have cost. I am not trying to step on your toes... only suggesting a more simple approach.
If the pics will be uploaded Saturday we will have until Tues or Wed to get the order finalized then submit it after the cut-off time and schedule delivery for Friday, then you could just bring the whole box to the meeting and everyone could pay you cash. I might be in for one if they have something nice in stock this weekend.
Hope that helps,
-- Kevin
EDIT: You could also state that anyone not picking up their clams at the meeting may have theirs sold if there is someone interested there so you aren't stuck with them.