> Is there a reason to keep it at all if its obsolete, or should we just > delete it?
The only reason I can think of why someone might still want that version is if they're doing hacking on a pre-v10 branch and would like to indent accordingly. If we have someplace for historical versions, I'd suggest moving this tarball to there, and replacing it with a README that says "go here for pre-v10 pgindent, or there for modern versions".
Add it as a branch in the git repo and backpatch the pgindent README?
Hardly seems worth the hassle. It's not like back patches need tons of worry about pgindent etc anyway.