Top Post Terminal Bolts

No, I don't want to post a wanted thread. I want to know WHERE to find something. Thank you.

I am trying to find a source for either brass or stainless top post battery terminal pinch bolts and nut. 5/16" x 1 1/4". I am having difficulty finding anything but zinc plated steel. McMaster Carr does have the PTFE coated red and black bolts, but I want brass or stainless. Thanks.
https://www.ebay.com/itm/325562274436