I googled a bit and found this little gem:
Good news: There’s a standalone tar.exe among the UnixUtils suite (gzip’s there too). And in their characteristically absurd foresight, those devs included an arg to manually set the mode of things as they’re archived.
tar --create --mode=777 -f "archive.tar" "TopDir"
Bad news: it’s one arg that applies to everything.
Technically this exercise can end here. Adding everything as 777 will make scripts work, at the cost of executable jpegs and extra glowy terminals. To do it right though, we’ll have to make multiple passes, walking the tree and only add one kind of thing at a time (dirs, files, scripts).