TOS SN-55B, SN-63B and SN-71B Lathes: Operation, Maintenance and Parts Manual. TOS SN-55B, SN-63B and SN-71B Lathes: Operation Maintenance and Parts Manual. The Operation Manual has links that point to illustrations in the Parts Manual. Manufacturers: TOS Skoda Models: SN55B SN63B SN71B Contents: Operators Manual Maintenance Manual Parts Manual