Has anyone worked with this speed display?

There are 14 jumper sections; one for each number segment. Each of these segments have 3 jumpers...

JP1: on turbo, on low
JP2: off turbo, off low
JP3: off turbo, on low
No JP: off turbo, off low

What's missing is "off turbo, on low" and I am guessing this has to do with JP2... Maybe something with a combination of two jumpers that would allow a segment to turn on for low speed and not for turbo. I am scared of shirting something by giving a try to two jumpers without any documentation...