1965 Valiant brake woes

Thanks all for the suggestions, insights and links.

I've tried since day one to get the "stock" stuff working correctly.

I have sh*t brkes and leaky wheel cylinders, what should i do? Fix the bad parts .... OK, did that.
Still have bad brakes .... fix it with more stock parts, the 10" drums should be sufficient. OK, did that.
Brakes still ain't great, should i just swap to discs? Nah ... the drums should be all you need. OK, I'll optimize what I have. Did that.
This cobbled together mess still ain't optimal and is starting to fail. Again.
That's how I ended up here, with a second post.

I hope the Raybestos master cylinder and adjustable pushrod solve the issue. A buddy has a stock distribution block he's going to let me have.