Re:"Upgrade" to 1.7.2? How?
There should be no new features between 1.7.x versions, and therefore no database changes needed.
If by reinstall you mean rerunning tiki-install, you should have to if you rewrite the file contaning database settings.
You must check that the files you changed have not been fixed (but IMHO it wouldn't matter much), then replace 1.7.2 standard files by your modified ones.
;){kind=link}
;){kind=link}