Originally Posted by
Mike Mills
Restoration - restoring to original condition
Repainting to the original color, without replacement of the factory decals, is a preservation (at best).
Replacing the derailleur drive train with a single speed is a conversion. Luckily, it seems you've not done any permanent damage. Did you keep the parts you removed?
What about a repaint with as close to the original color but taping over the original decals (and keeping) because they were in okay condition?