I bought those in Czech republic but i know Phil hobbyshop is selling them also in the US.
Its the Detail master DM-3201. One tip, dont use it because the diameter is too big for the Willys
There is not enough space for it unless you cut the body of the car or lower the engine at the front.
The engine is little bit tilted backward, I lowered it so that i could use this distributor. I ended up with exhaust that did not fit anymore, same for radiator hoses, the electric fan on the radiator and more extra work
Search for Parts by Parks, prewired distributor kit. This one is as big as the original plastic one in the box.