I am having issues with getting my bike to shift into it's lowest gear in the front properly. It will shift back and forth fine, but for some reason when it goes to the lowest gear, the chain lands on the chain ring's teeth instead of fitting neatly in between! This consistently happens and after a pedal or so it falls in between. Here is a picture.



This is a Shimano 600 component group from the late 70s if that matters.

Thanks for reading, I'd appreciate any help!