It's a 10L (SB Heavy 10) that I refurbished in the past few months. From the company logbook at South Bend it comes back as:
1. Serial Number: 19118RKX
2. Catalog Number: CL187RB
3. Size: 10"X4-1/2' (Heavy 10)
4. 1HP; 208V/3PH/208V
5. 1800RPM
6. Ship Date: September 24, 1973
7. No extra options are listed.
I just got the aligator clips for the belt yesterday so I think I can be making chips this weekend ;)