The Italian Road Bike Mirror attaches to the outside of the bar under the tape, so that might work.

https://www.italianroadbikemirror.co...SAAEgK1P_D_BwE

And it's a fantastic mirror. Significantly clearer and better field of view than others I've tried. They sell blems on their ebay site at a nice discount and I couldn't find a blemish on the one I purchased.

https://www.ebay.com/itm/Italian-Roa...75.c1#viTabs_0