Ditto on Velvac.
Look the mirror housing over very closely for the manufacturer name.
Sometimes hard to see.
I snapped my mirror assy off of the shaft and got a replacemenr from velvac.
Let us know how you make out.
Just thought of this:
Go to:
http://www.velvac.com/RVs_only/order_online/order_online.html
And select one of the options at the bottom of the screen.
This should get you just where you need to be.
If you can't get anywhere there, call for technical assistance.
I did this and they were a great help.
Again, keep us informed of your progress.