Contact Ramco Engineering. They supply mirrors for most of what Jayco makes.
https://www.ramco-eng.com/
I believe your motorhome uses a 1350 Series mirror. They will sell them individually or in pair and they will sell them with or without the arms. Also, if your have an embedded camera you will need the InVue option.
I smacked a tollbooth with my Alante... I called them on a Monday and had the mirror in my hands on Friday - IN to NJ. They are super helpful, just have your year, make, model ready and make sure they know what class (A/C) motorhome you have. I paid $500 for a complete passenger assembly with an embedded camera. Without the camera I think its about $300.
Good Luck!