Hey @joebods I downloaded your file and 2 things I want to share:
1. I think you did a great job modeling the treasure chest
2. You definitely need additional training on UV unwrapping and proper use of seems. You probably already know this. I am no expert myself but typically if there is a sharp-ish corner then there needs to be a seem to handle that bend (most of the time). This is an intermediate/advanced topic to be honest (at least I think it is).
I re-posted your blend file to your shared location: Treasure_Chest_edited_blanchsb
It’s not perfect but it is much better. I also packed your blend file. You can unpack it if you need to.
Let me know how I did. I definitely messed up a lot of your workflow doing this so I don’t recommend using my file if you need to tweak things (I removed all parent and linked duplicate relations and deleted one hinge that I could not for the life of me figure out it’s uv problem so I just duplicated another hinge and put it in place of the deleted one.)
The main metal rim and the lock piece rim and the hinges were the main problem areas. They need a little love and then you should be able to get a better texel density on your UV’s.
There are some great uv unwrapping vids on YouTube. I personally learned a lot form Blender Guru on this and I believe I remember @spikeyxxx posted a great UV unwrapping video link to another blender guy who is an unwrapping master.
Blender Guru UV unwrapping an Anvil
Advanced UV unwrapping magic tutorial: By Daniel Bystedt
I also got UV packmaster pro add-on to help me quickly try and fix your uv’s and make most use of your uv map.