162591,
I have the following South Bend "Heavy 10" lathe shipped out from South Bend Lathe on August 28, 1945,
The original purchaser was not disclosed to me at the time I was given the shipping date information,
by South Bend Lathe in 1972 or 1973 when inquiring about parts,
I do not have a copy of the serial number card.
Lathe ID tag reads: "Swing of Lathe 10L", "Length of Bed 4-1/2", "Catalog No 8187RN"
Spindle is threaded 2-1/4 x 8 with 1-3/8" bore.
This is the 12 speed, 1" 5C collet, Toolroom Lathe,
with telescopic taper attachment, single tumbler gearbox,
and tubular steel frame sheet metal 5 drawer UMD Bench No. 1648-5D-1045 with integral chip pan,
The bench is similar to Catalog Number 1796 but has 2 drawers in the center in,
addition to the 3 drawers at the right hand end. There is a door for access to the UMD at the left hand end.
Motor and Controller: General Electric Model 5KC73AB380A, Type KC, 3/4 HP, 115 V, 1725 RPM instant reverse motor
(I am quite certain this is the original motor) with original South Bend supplied Cutler-Hammer drum controller (SBL Cat. No. 790, C-H Publication 7146) mounted on the South Bend supplied cast iron headstock controller bracket.
I purchased this lathe used from D&H Machinery Consultants, Inc., Toledo, Ohio on October 10, 1972, for $550.

The motor shaft diameter is 3/4"
and the motor pulley is a two step steel or cast iron pulley with outside diameters measuring 3.405" and 2.095".
That would be PT2121NR1 on your list.
The countershaft pulley is a two step cast iron pulley with step diameters measuring 9.125" and 10.000".
The parts list indicates this pulley to be AS2547RL1.
The motor belt is a Dayco 5L450.
The motor belt tension is perfect with the belt in either pulley position without any adjustment necessary beyond the initial setting.
I believe the pulleys as well as the motor are original to this lathe