While helping in the forums, we regularly run into VI's saved under an older LabVIEW version, modify it and post it back, usually saved in the latest LV version. Soon after the original poster complains, asking for a converted copy.
Years ago, I even proposed a small starware utility (Get VI version) that returned the LV version any vi was saved in. Unfortunately, it stopped working with LV 8 (and didn't recover since... ;)).
I found several proposals for displaying the version number (for instance here and here), but they are related to the application version and not to the vi version. None corresponds to this very basic idea : as long as a vi has been saved in a version different from the one in use, display it as unsaved (using the usual star), with the original version number attached. Something like this :
Alternatively, when saving the vi, the programmer could be proposed to choose the former LV version.
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...