Good luck. Numrich didn't have them, you might try Jack First. Having said that, not having a hammer spur leaves you in a really bad situation if, for several reasons, the trigger won't move and rotate the cylinder/cock the hammer.

This can be caused by: glove material pinched between frame & trigger that won't let the trigger go all the way forward, debris under the extractor, high primer and cratered primer that enters the firing pin hole in the breech and locks the cylinder. Burrs on the firing pin hole can also get caught on the firing pin indent in the primer.

All of those can be cured by a hearty yank on the hammer spur.