Is this servo usable for position control?

I have 3 Japan Servo DC servomotors, which were replacements for Zerox
copy machine parts, now surplused.

Detailed information about this motor is available at C&H:

http://www.aaaim.com/cgi-local/shop991/shop.pl/SID=262414781538/page=D
CME.htm#DCM8757

This DC servo motor has a tach output, but no encoder per se. Motor
speed is controlled by pulse width. If I count the tach pulses can I
use this to establish positions reliably? And control this
position with the 24 volts DC supply?

At $12.50 it is cheap, but is this it's only virtue? I actually paid
less at a Canadian surplus source, but have no hookup information.
Power supply connections are straightforward, but does anyone have the
other hookup info for this device?

Looking forward to replies,
Grant