I've got the same problem. In cause I've got a LHD car, the right mirror is the "wrong" thing.

Adjusting the mirror again and again, and never a good look back.

But not shure about a good alternative I look for a cheap way.

So this mirror is my way to cure rhe problem. https://www.louis.de/artikel/scooter-spiegel-retro/10028354?list=3a0f4a22db7d2275546ebcd2e8176474

But how it works?

First push the black rubber up and you have a sight to a grey plastic. This is a stem-stop. You must fiddle it out. Keep it at a good temepratur. I use a spanner
to lift it up. Than the upper stem of the mirror slides out of the lower stem.

In cause the "Louis-mirror" is 9.9mm and the Morgan stem is 9.3mm the plastic must leave or sanded up to fit.

But you must work at the "Louis-mirror" too, you must short the stem to your own size of wish.

May be not perfect like the bespoke mirrors, but a good working alternative.

René

2018 plus4 (sports green)
with a homemade really shiny red tinted dash…