Thank you for responding!
Yes they all have the same image and resolution. They will fit perfectly on the smart object.
I read that post you posted and it got me a little lost. I tried putting that code and it took me to the select folder but it wouldn't let me select folder. I'm running on a Mac CS6.
Any recommendations would be much appreciated!
You could try adding an append to that forum describing the batch process you would like to automate. The author of the script c.pfaffenbichler appended there will more then likely help you with that script. I'm on windows he is a better at Photoshop scripting then myself. The code I see in that script is to interactively select a replacement files not a folder for each smart object layer of the active document I think. Try using his open dialog and navigate to the replacement file's folder then select the replacement file. It is not a batch script. You would need some design work to batch something like that, For selecting source files identify smart object layer and replacement file and not have an interaction with the user for object being replaced.