outboardnut, The only thing I ever tried years ago was a truck tire valve. Pretty good match for size but it’s challenging trying to get a good enough grab in a vise to drill out the insides. I didn’t have a Dremel at the time, I do now, maybe it’s time to try again using that.
I know you’re looking for substitutes probably to cut down on the cost but I think Big Rich sells them for a reasonable price. Not knocking NYMarine, just that Big Rich is US so that’ll save a few bucks.
