Well, I do not think it as straight forward as it looks....
The calibration of the instruments is the same as TZ, just compare the photos.
However, there are significant differences;
Firstly the orientation of the numerals is completely different, TZ - Cannot vouch for TZ2 - are as all standard Alfa gauges. Rotation starts at about 7 o'Álock to 5, as posted by ARGTAReg, above. However, I do accept that the rev gauge in question is more appropriate for racing, since the rev indicator will be in the 'sweet' vertical position more often when racing.... but in my car the vertical position needs to be at 6 o'clock otherwise it is obscured by the wheel.
Secondly, no TZ has auxiliary information within the instrument ie, RISCALD. or GENERAT.
Thirdly, it is odd that the two instruments each have a GENERAT. indicator, surely only one needed?
Finally, Domo75's gauges at 125mm seem small compared to TZ instruments posted above....but nothing to hand to measure!
Just my take on it all....
Edit; I think all TZ production finished by 1967, but instruments in question are dated 14 Giu 1968!
Last edited by richards; 03-26-2019 at 01:17 AM.
Reason: Add 14 June 1968 info.