Acrylic glued to painted alloy panel

I'm attempting to repair a caravan alloy side panel. The usual trick of using filler, smoothing and painting cannot be used due to a difficult to match ribbed pattern on the existing area of panel - so the plan is to stick a flat panel over it, a little way proud of the surface, rather than just the minimum thickness, with neatly rounded corners to make it look a bit more intentional than a patch. I did plan to use a piece of alloy, which might be difficult to get in place flat. Someone has suggested 6mm acrylic sheet might be easier to get flat.
I'm just wondering if I might be struggling first to fix it - if the surfaces were roughened, would ordinary sealant stick it in place firmly and might be struggling to spray paint it?
--
Regards,
Harry (M1BYT) (L)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.