Both requirements are easy to meet.
If you're a vet and belong to the VFW , American Legion, etc. that's all you need.
If not and you need membership in a CMP affiliated Club you can join the M1 Collectors Club for $14.
If you are 60 years of age or older, a vet or law enforcement officer you don't need any other proof of marksmanship activity.
If not, documented proof of any activity that included live fire training or shooting is sufficient.
Like a CCW class or hunter safety class as examples.
Even organized airgun shooting can qualify you.
Thanks for the info. I thought I had done the research but apparently my research skills were lacking. I am retired military, ex-LEO, and have concealed carry permit so I meet most of the requirements. Just have to join a club. Thanks again.