Wondering if anyone has used these?

Bought a full set of Aurora gauges for my project. Having issues with the Tacho. Face is 0-7000 RPM which is what I want, Instructions are for 0-10500 RPM!

I have spent the last 3 days speaking to the supplier (Autoloc) who to be honest have proved to be completely useless. They have no idea!

Oh and car isn't running yet so I cannot just try it in the car!

Has anyone else used these gauges and found the resolution to this issue?

I am about to take the whole lot back to the shop... but thought someone might know the answer

Cheers

Trog