yet another question, 'Is there an Un-do Button?'

Support Basics & Interface
1

Is there an un-do button

2

Only in Mesh Edit Mode. Look at the bottom of the 3D View Mesh menu for commands and their hotkeys.

Otherwise there are a bunch of other workarounds that will lessen your need for undo. Do a search for undo in this forum, it should bring up plenty of similar topics.