There are no restrictions. See post 101, 112, 116, etc. on this thread. The 60 day rule only applies to Corportations and Labor Unions, not 527's.
Are people are not sending in money to swiftvets because they falsely believe the time for is adds over soon? (If someone can refute posts 101, 112, and 116 do so, but they seem right to me.)
I heard O'Neill on a local radio station and he was asked if the Swiftvets are a 527. He stated no they were not, something about small donors and can't remember what he termed them but not 527.