Electronics 2000

hi....I don't know if this is the right forum to ask on but I hope someone can help me

I bought a retro car accessory from the 1980's called a cal custom performance timer

it's new in the box but missing the magnetic speed sensor

I have the magnets that fit to the prop shaft, it's just missing the electronic sensor seen in pic below, does anybody know where can I get a suitable sensor from?

Thanks

Make one... not sure of the exact spec but it will just be a small coil... one side to chassis the other side to the black box.

Tar&stuff.