Great idea, I think this can work well.
There's some First Age homebrew stuff in this homebrew collection:
https://discord.me/theonering (direct link:
https://drive.google.com/file/d/1SvUxhv ... share_link).
I'd broadly do the same - turn things up to 11 for various cultural virtues/blessings, maybe grant PCs two attacks at Valour 2 etc and increase the engagement limit to 4. Same broad rules framework just with things amped up for a heroic scale! Easy to map various cultures to First Age equivalent (linked document has some suggestions).