Euro mount outdoor longevity tips

[sawatch]

I've got a raghorn I euro'd and am considering hanging outside on a new barn I'm building. I've seen elk on old ranch arches in my area, and they are pretty chalky. Was curious if anyone did any prep work to extend the life of the mount? Poly on the skull or antlers? Period oiling of the rack? I know overall it's a losing battle to UV, so just spitballing some ideas to extend the life of the mount. Thanks!