We have this car frame and I am not sure what it is for. The left grease cap is Chevy and the right one is ford and I believe the frame to be from something around the late 20’s and early 30’s. Anything will help even small details.The rear axle is disc brakes with a split case diff, not one with a cover. I could not find any design related to the leaf spring design. Leaf springs look the same all the way around design wise.