I might wear a small feather like you see in some regimental tams if I had a decidedly non-military badge over it. It would make a nice backer and a nod to the regiments at the same time for those who are in the know.

Trust me. In Oregon, no one will know or care about the origin. It will only be a feather in your cap so to speak.

I wouldn't wear such in Scotland for the reasons Chas mentioned, but, in the US, it won't mean a thing and few, if any, will ever think about it. If you like it, wear it.

Or, you could do like I do with my Black Watch tam and red hackle: put it on the shelf for a nice collectable.