Which restaurants where?
I don't think too many take them anymore. I got one to take mine when my check card didn't work (bank had cancelled it due to potential account compromise and I didn't get the letter)....basically they only took it b/c I told them it was "take it or don't get paid".
Usually if an establishment accepts checks, the check# shouldn't matter as long as it is not a temporary check. Address should be printed on them and match your ID. They may want you to write your phone# as well.