This looks like a job for Lingua::EN::NameCase.

It misses on 'DeVelera', but gets quite a few others. Perhaps you could patch it to handle some of the names it currently misses, and submit your patch to the author?
(or maybe the 'EN' is being narrowly interpreted...)

use Lingua::EN::NameCase qw( nc );

foreach my $name(qw( mcginley macgee develera )){
   print nc( $name ), "\n";
}
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