<VV> Door mirrors?

[Jeff Wilson]

Looking at varous vair pix on various websites, I'm wondering....

I'm seeing outside rear-view mirrors (on the doors) on lates that
are round, and some that are square/ rectangular.

Was there a change made at some point?

I've got a 65 with the round mirror- would prefer rectangular.

Are there later-lates that could provide a bolt-on 'donor' mirror, or
are there square mirrors from other similar-aged chevys that 
could be used?

Would prefer NOT to drill any new holes in door!

CJ Wilson