I have a 6 foot length of "O" ring stock. Super glue works well for both creating your own rings and fixing them in place....but the true magic moment is when you cut the length out on your own and it is such a perfect fit that nothing is needed to hold it in.
About making your own o rings, cut both ends at the same time with a new razor blade. Smooth, square, flush fit. Just a dab of cynoacrilate (super glue) less is more. It won't change the property of the ring stockbut too much will make a crusty mess. Less is more.
I have no brand loyalty. I dont think a mass produced part is universal. Make it yourself.
Amen brothers. Amen to no more drippy carb bowls.......rant rant rant. Good luck.