What does the registrar think? This will be one to haunt both owners. The gold car appears to be recently discovered. I vote for the gold car and would suspect someone grabbed an "unknown #" out of the registry to build the red one.
The gold one looks to possibly have had major damage to the right side - 1/4 replaced, inner & outer wheel wells, RR floor pan, R rocker. Maybe builder of red car saw it sitting w/damage and figured it would never be rebuilt.
But...... the red one does have a signed glove box door.