Dan,
Your mirror is the same as the one I found online. Those detail lines along the back are what makes me think it would look era-correct, or at least close. But it wasn't $5...I'll double check the price but I want to say it was about $20-30.
But here's my concern: Can you actually see out the mirror well once its mounted? I don't mind drilling minimal holes (eek!) if necessary but not if I can't use the mirror worth a darn.
Going looking for that repro mirror now...."I'LL BE BACK..."
