Passenger side mirror glass for 1974? Which Dorman part number?

[Busterjohn]

My mirror glass fell out of my passenger side mirror on my 1974 C3...I ordered one online that should just stick back on with double sided tape...they sent me a Dorman brand glass but was the wrong part number because it was oval shape...does anyone happen to know what would be the right part number...I keep getting different part numbers from 51010, 51005, 51001, etc...I don't want to have to return another one.

 

[Vettehead Mikey]

I don't see any mirrors on the Dorman site that are even close.