Well there are plenty of sources for nibs but what I am looking for is the nib coupler. The part that in a kit is press fit into the tubes that allows the nib to be screwed onto.
I did see that goldennib.com has windsor/churchill couplers so i might get a couple from them before diving into thread chasing my own couplers.
While I'm at it though any idea what tap would be used for the most common nibs?