Well, yes, but it will need modifying.
In 1969, the 911 was equipped with a CDI and a small cylindrical tacho driver device. This sends a larger tach trigger pulse to the tacho.
In the later cars, the tach trigger is driven off the points, a nice 12V pulse that just isn't big enough to trigger the 1969 tacho.
To get around this, I change a resistor in the tacho to allow the smaller signal to trigger the tacho.
This will probably work with earlier, non CDI tacho's driven by a CDI, or MSD or similar.
This works on PCB's that look like this inside...
The resistor to be changed is the Orange White Orange one.
This is changed for a 6.8K Ohm 1/8th Watt.
See below
And here its is re assembled, and working.
Venture into modifications at your own risk. There are a multitude of different tacho's and ignitions systems. They are not all the same, and this modification may not work with all tacho.
Have fun
Tim