Possibly the easiest way to use an autosave project is opening it and then use Save As..
That works, too. Thanks, Harm. Just wanted to be sure.
And it saves you the trouble of copying first, then renaming, then opening the renamed file and then using Save or Save As...
One thing that I'd like to point out is that the incremented AutoSave files are not in sequence, relative to Time/Date. If one has the default of 5 AutoSaves, these will appear as [Project Name]_001 through _005. When looking in that folder, set the View to Details, and look closely at the Date/Time for each file. [Project Name]_003 might be newer, than _005. Each AutoSave file is overwritten, and AutoSave will cycle through the numbers set. It's a FIFO situation and has tripped up many. Check that Date/Time carefully.