Aaron DavisHi Aaron,
I realised I had the same itch! I think the custom google search would do the trick. But I though it might be better to have something built in to WordPress. I found Search WordPress by Custom Fields without a Plugin | Adam Balée Designs, LLC. This requires you edit a functions.php file. I’ve already got one in my child theme so added the code there. It works.
Thank you John. From my initial tests, this seems to be working perfect. Very happy.