I had the 1969 version of the 120 Roadrunner...got me thru my first year of HS when I got my permit/license.
I thought maybe they'd be the same bike, but I don't see the dual range lever on the left case. Mine was an 8 spd / dual range, with an 'endless loop' shift pattern.
From neutral, down for first...down again for 2nd, 3rd, 4th - and down again you were in neutral. Up for 4th, 3rd, etc.
Great little bike, had the same rotary valve engine that was a strong runner.
Once I had my license though, I craved something big enough to go places and bought my X6 Hustler.
These 120's are cool though. I think this one might be newer than a '64 though, maybe a '67.