On a rewire job, unless I've got the headliner out, I just leave the old ones in place and disconnected (they're retained with spring clips) and fish new wires. No sense gambling on the old insulation being in good shape!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!