General RV has 'em on the rack some of their stores.. I'll be picking one up in a bit over 2 weeks if I'm not mistaken 4 weeks if I am mistaken as to which store..
About 65 dollars as I recall... At least I think it was General RV. may have been Camping World.
It looks like a Velvac brand mirror. Parts can be ordered direct from Velvac on their website and the site helps identify the model.
https://www.velvac.com/where-buy/order-rv-mirrors
Don't overlook used. We picked up an identical mirror at a junk yard. They had a Winnebago product and the mirror was identical to our Rexhall Aerbus. Don't look specifically for one for your Monarch. The used mirror looked good and cost $100.00. The replacement from Velvac was more than $400.00.
Thats a Ramco Engineering mirror..( It says so right on the mirror), Go to Ramco Eng. website and you will find the replacement glass ,, know your model number..( also found on the frame) >>>Dan