I recall having occasional light leaks when using my mom's old Ricohflex. Looks like (from the looks on an auction site) there is a length of black yarn running around the inside back. So make sure that is still working as a light seal. Maybe an easy do-it-yourself repair.
As blee1996 says, the lens will have an interesting "signature." I've come to appreciate this in vintage cameras. For me a "good" lens in a medium format or large format camera can be worth using. You might enjoy the same.
This could be the knock-around camera you toss in the backpack when you don't want to risk your Yashica...