One of the most obvious mistakes we see on concours restorations is over-restoring. Yes, you can get things too perfect. Classic Mustangs were mass produced in poorly lit, dusty, dirty conditions by people doing a monotonous job day after day, week after week while they wondered how many minutes it was to break time. These striking classics were not perfect to begin with. Sound deadening was slopped on the firewall. Hose clamps were installed close to specification, but not dead on. Screws were installed cockeyed. Obscenities were spelled out in the sheetmetal with wire-feed welders. Weatherstrip adhesive was used to excess. Sheet metal was misfitted. Do the best you can, but do it with a little bit of apathy.