I just started flying with a pvt pilot applicant. Already has 40+ hours, soloed 172, passed written and has 4.2 solo x-country. I see on his student pilot license ( medical ) his previous instructor never singed it for solo x country at the bottom. Question is does that make his 4.2 hours void? I started flying with him because he bought a C140. His first instructor is 1200 miles away so not handy to have him sign it. Thoughts?