Thank you. This PDF of the actual Senate Rules is what I was hoping for.
Two important notes from this:
1) I see nothing in the rules requiring Senators to be present during the trial or a ban on campaigning during the trial. Since the vote may be held at any moment, it’s a matter of logistics that the Senators may need to be in Washington to vote but there’s nothing that specifically prevents them from being elsewhere, only that if they were campaigning instead of sitting in trial, they may be asked to explain why they thought campaigning was a higher priority than casting a vote.
2) there was this:
“IV. When the President of the United States or the Vice President of the United States, upon whom the powers and duties of the Office of President shall have devolved, shall be impeached, the Chief Justice of the United States shall preside;”
so it would be Chief Justice Roberts that would preside at trial, not Mitch McConnell or any other senator.