Unfortunately I see a mix of leather pieces and some serious wear on the headstall, poor repairs done.
That does not make for a harness worth much money to me.
Some parts you display look more like riding tack not driving harness too...
I don't mean to be rude as its not my intention but maybe $200, maybe.
There is to much mismatched, broken hardware, poor repairs and that makes what is present questionable in quality and future usefulness.
I'm sorry.
🐎... jmo.