Per my vast math skills, I think what I need are 14 ga., J-bend, 270mm spokes...pls don't trust that 100%. But I think that's what 10.625 inches converts to. And yeah - my trusty tape measure verifies 10 5/8".
Using the handy Google converter, 10.625" = 269.875mm.
I also have a couple of Bates Nationl Rules. Stainless steel, inch and metric. Hook the J end of the spoke on the edge and get the SAE units, flip it over and get the metric units.