Think it's a U3. Thumb is an add on I think. Whoever added it did very nice work. The relief isn't set right and the bucket reliefs before the thumb. I have to slightly run the thumb open to curl the bucket while pinching something. Any ideas what pressures I adjust to? I think this is the pressure relief for it.
Also it easy to swap to standard Hitachi joystick button control for the thumb. The foot pedal is a pain, I'm so used to joystick like on the 200 and 330 I have a bunch if seat time.
On a full size machine I usually set them at 1800-2300 psi. You might just have to play with it a bit. To switch it over to joy stick control you'll need a DO3 solenoid valve and sub plate, plumb into the pilot system and go to the top and bottom control valve auxiliary ports.
The pedal I'm pretty sure is electric. At least there's a wire harness there.