The "slant" might be explained in that they were both "righties", Thanks for posting additional images. I especially love this quote by STAN MUSIAL who saw quite a few curve balls in his day
During his career, Jones was known for his sweeping curveball, in addition to a fastball and changeup. Stan Musial once remarked,
"Sam had the best curveball I ever saw... He was quick and fast and that curve was terrific, so big it was like a change of pace. I've seen guys fall down on curves that became strikes."
____________________________
Buying Vintage autographs 19th Century and dead ball era my specialty
jim@stinsonsports.com