Does the bumper cover have a perimeter that overlaps the bumper in a decent amount? It may be plenty to just RTV the perimeter well, inside the cover, to make a thick line which holds both well enough.
Low supplies have drastically raised prices of countless things, the inflation stats are complete lies, massively inaccurate. Unrelated by scary to think; I was browsing eBay months ago for various SBF parts, engines etc. I noticed a crate engine for $14k+, wondered what that could be, and it turned out to be a simple crate stroker, with an aluminum block. I was stunned, the AL block used to be a $4kish part, the Dart version. I checked quick and found the cost had jumped up to about $9k just for the block from Summit, $10k to $12k from other sites. Lack of parts has made prices skyrocket on tons of things.