DON’T USE THIS DEVICE NEARBY ANY MEDICAL EQUIPMENT LIKE PACEMAKERS ETC.
Oh common… you can use a 2SC2078, 2SC2166, 2SC2312, 2SC1972, 2SC1972, 2SC1921, 2SC1969, 2SC1945, any of those should be fine, circuit is very primitive.
Here is a close view of the PCB:
Definitely not, and everything can be made from scrap parts…
Small coil and big coil:
Redraw of the PCB with Eagle:
Assembling the 45V batteries rig, voltage must be over 30v-45v max, be careful to don’t hurt yourself.