Missing T-85 Power Button

Hi. I recently picked up a T-85 tuner it is in very good shape and work fine, but it is missing the power button. Maybe button cover is more accurate as the underlying button is there and works when pressed. Thus this is more of a cosmetic issue, aside from a couple scratches, it is in really good shape so having the button would be nice.

I have attached a picture to show what is and isn't there.

Any thoughts on how to proceed such as what other models would have the same button so I can inquire about dead parts units? Anyone who might be especially likely to have something that would work?

Thanks for any information/help.

Chris