Thanks for the reply. Yeah, now I see the full bridge rectifier. It's odd they used two 1A diodes and two 3A diodes, but it works.
I updated the schematic, so it looks a bit better. The "Triac" 2N4990, is specifically a Silicon Unilateral Switch (SUS), so I changed the schematic to reflect that. I am not sure the pinout on pins 1 and 3 (anode and cathode) as the datasheet didn't look clear on the orientation of the picture where the pins are. However, I drew out the PCB in EAGLE and the silkscreen on the PCB matches the real one that I traced, so if I reproduced the PCB, I know it will work, but my schematic "might be" backwards.
I've never made a motor controller that uses SCRs and SUSs, so this is new territory for me. I am used to MOSFET drivers or H-Bridge. I'm also wondering where the smoothing capacitor is for smoothing out the full bridge rectifier.
This controls a DC motor rated for 120V DC, but uses this board to convert the 120V AC to do so.