Now how did I know my response was going to rope me into something more...
First let me explain I'm not guaranteeing ANY of this .. I haven't tested it, and I'm not going to .. I only mentioned the first issue that I spotted and there may be others.
To overcome JUST the issue I spotted, and assuming you're reinstalling the same distro/version, instead of generating a "sources.list.save" and copying it over the existing sources.list, why not copy the original sources.list and the entire sources.list.d directory.
(in fact why not try copying the entire /etc/apt directory .. renaming the original rather than deleting just in case)