Although LabVIEW seems to know what version it was previously in, (it shows this information when you close a VI without saving and it promts you to save, you can click 'Explain' and it says it was in a previous version and what that version was) I don't think you can get that previous version number through a property node or any other means.
One way you might be able to it would be to actually open the VI, then check the VI property "Modifications>VI Modifications Bitset" property. If the output of this property is zero, then no changes have been made to the VI, so that would indicate that it is saved in whatever version you are running the tool in. If this number is anything other than zero, then something in the VI has changed. Unfortuately, you won't know for sure what has changed. It could be recompiled due to a version change, or it may have found a sub-vi in a different place. You would then have to open the VI and look for yourself. It's not exactly what you want, but it might get you close. Ed
