need help with swapping out CR 125 frame 90 to 95

A friend just gave me a nice 1990 CR 125, but there is a hairline crack in the rear of the frame near the swing arm mount.

I know where I can get a nice 1995 frame and I think the two are interchangeable. anyone certain? I don't want to shell out the dough if its not gonna be interchangeable.

Thanks in advance for any and all assistance.

thanks chris, this is all happening fast, so my time to research is limited. so many parts were listed for cr 125 90-97 i though maybe i would luck out. the frame was only $100. I will either keep lookin or get it welded. thanks.