As to your election office, see:
http://elections.state.wi.us/municipalclerkslist.txt
As to whether you can look at the Application for Registration forms, I called my local office and they said they would not show me the entire form, because it contains date of birth and DL number and SS number. But. . .
They will give me a list of names and addresses of those who have been registered on a mass scale. So at least these can be checked. The clerk would probably also let you photocopy at least the signatures on each form.
A copy of the voter registration form can be found at:
http://elections.state.wi.us/pdf/EB-131%20Voter%20Registration%20App.pdf
As to wearing a suit, I wouldn't think that would be necessary. Just be courteous, and persistent.
Hope this helps. Do all that you can.
How they do it:
http://projectvote.org/?114