this is before 1934 ,there is no writing about super pin tumbler/graphite. It only has 2 (4) pins holding case on body. Pete, this is the one with the older sager keyway (y91) A y54 fits the change side .but really needs the larger blank ? The Master side has the 999CA blank and has a master pin in #2 & #5 holes Click image for larger version.  Name: 2pin 1.JPG  Views: 6  Size: 1.34 MB  ID: 18327Click image for larger version.  Name: 2 pin 2.JPG  Views: 6  Size: 1.17 MB  ID: 18328Click image for larger version.  Name: 2 pin 3.JPG  Views: 4  Size: 1.16 MB  ID: 18329Click image for larger version.  Name: 2 pin 4.JPG  Views: 5  Size: 1.22 MB  ID: 18330Click image for larger version.  Name: 2 pin 5.jpg  Views: 4  Size: 558.7 KB  ID: 18331 More pic's of the inside next.
These pins on the bottm do not go thru body,IF you drill you will enter the plug cavities on lower area. No i did not drill thru,not being sure i drilled a little and they came out with an easy out. Case seems 1/16 shorter than my other 937's bodies,not including base.