I also ordered Dow Corning 795 silicone which is the proper adhesive/sealent for plexiglass.
We had hoped to salvage an intact piece of the original to use as a template but they all shattered on removal. It was easy enough to make the correct shape when we had the frame removed.
| The edge of the protective film was cut away before seating the plexi in a bed of Dow 795. Before the 795 fully set, we peeled away the masking and tape. |