I'm always a bit skeptical of charitable organizations and I haven't first-hand vetted this one, but it's Mission is dear to my heart and it involves wrenching on bikes. I became aware of this organization through Michael Coffey of Voodoo Vintage. I thought it might be of interest to members here; not just financial support, but also volunteer opportunities to help vets learn the skills of our hobby.
https://www.combatbikesaver.org/mission-first.html
https://www.combatbikesaver.org/mission-first.html