I bent up some thin angles for under the windows, and Hysoled those. They are similar in thickness to the window frame material. The side pieces over the baggage opening are thicker flat strips, attached with non-cushioned Adel clamps and a little Hysol.
Paul Z - I wanted something where I would be able to “zip & un-zip” the Velcro without having to mess around, particularly to access my ELT. I wanted it to look clean also. I’ve seen too many that look messy to me, with the velcro peeling up here and there, even with zip ties