Water leak by way of slideout

[Woodstock-WO]

During a strong and powerful rainstorm water came into our 2019 Winnebago Micro Minnie on the floor right at the bottom of the sofa's armrest. Upon inspecting the outside of bump-out, I noticed that a plastic or vinyl strip was not flush with body of RV at the top. The vertical strip is held in place by several rivets at the top and at the bottom. My question is "How do I fasten this plastic strip to make it flush with and attached to body of RV?" I am hesitant to drill and insert more rivets. Would an application "3M Superweatherstrip and Gasket Adhesive" be a good possibility to make this repair? I would be grateful for some advice. Thank you!
Woodstock

 

[backtrack2015]

No promises it’ll pay dividends, but an annotated photo or two might really help with your inquiry.