Thanks, Larry. I took a look. I don’t seem to have a Solutions link under Galleries to activate it (Go to Site Settings | Galleries | Solutions, select Solution and Activate (ribbon button)). Not sure if that was just an original step prior to adding it to the Enterprise Project Types.
I have successfully created a template, updated the Enterprise Project Types to use it and confirmed that new sites are now being created with the new template. I haven’t found a way to update site that were published prior to the new template other than recreating everything manually for each.