That approach won't work for constants inside structures...the AllObjs[] property of the TopLevelDiagram class does not recurse into structures.
The Traverse VI is present in LabVIEW 8.5., just with a different name/location: [LabVIEW 8.5]\vi.lib\Utility\traverseref.llb\TRef Traverse for References.vi.
Versions 8.6 to 2009 scripting can be accessed using these instructions.
https://decibel.ni.com/content/docs/DOC-4973
I can't remember but I think 7.x era you used the SuperSecret INI key, and I can't remember the steps for 8.0-8.5. In any case scripting existed in some form back that far. Try this VI that I saved back to 8.5. I don't have 8.5 to test it on so no idea if it works.
Get String Const.vi
NI week approaches. I'm doing a session on "Web Tech for Test and Automation" on Thus @ 2:15. During it I'm going to show off some open source LV Web Service code. If anyone wants to give feedback you can find the reuse code here. Any feedback is appreciated. It requires installing 3 packages and LV 2013 or later. Cheers.