904-906-908 Strange Rev counter? Any idea?

Hello, i have found from a friend this rev counter. He had it for long time and he says it comes from an old racing preparation team
and it's supposed to be 904-906-908 or other racing cars. Any idea or photos where it could be from?? 12000 RPM?!
Thank you all for the appreciated suggestions

<a href="https://ibb.co/cuTC9R"><img src="https://preview.ibb.co/hJYepR/dcdef114_61df_4340_8dcf_4ce25dd834b4.jpg" alt="dcdef114_61df_4340_8dcf_4ce25dd834b4" border="0"></a>
<a href="https://ibb.co/kngX9R"><img src="https://preview.ibb.co/kYzKpR/8b659cf3_793c_4272_96bb_475fd8a5d6df.jpg" alt="8b659cf3_793c_4272_96bb_475fd8a5d6df" border="0"></a>

Can you provide a closeup photo of the back showing the "IMPs"; it should be 30,000 +

Hi Dave, sorry for my bad english, i can't understand exactly what needs to be showed. If you can do a red circle on the photo or tell me how to narrow the photo i will be happy to do it..
Thank you

No problem. Here is the back of an 8000 RPM tachometer. Notice the 12V 24000 Imp in the upper left corner. This is what we need to see, although the 6zyl is also important.

Chronometric ...

here other photos from my friend, unfortunately no numbers on it..

<a href="https://ibb.co/jh7DOm"><img src="https://preview.ibb.co/dnBwb6/2018_02_02_PHOTO_00000067.jpg" alt="2018_02_02_PHOTO_00000067" border="0"></a>
<a href="https://ibb.co/jbxr9R"><img src="https://preview.ibb.co/dCsPUR/2018_02_02_PHOTO_00000066.jpg" alt="2018_02_02_PHOTO_00000066" border="0"></a><br /><a target='_blank' href='https://it.imgbb.com/'>image upload</a><br />

Sorry, I must have been asleep. That has to be an old style mechanical tachometer. The large threaded post on the back is where a cable would attach just like a mechanical speedometer. That puts it out of my range of knowledge.