The Mitutoyo parts list for DRO/Counter unit stuff shows this manual as
p/n 29624

The DRO unit is a white/beige box with grey front panel, 2 axis, green
digits, membrane keypad shown here..
http://www.kwagmire.com/shop/mituapl1.jpg

http://www.kwagmire.com/shop/mituapl2.jpg

I think this unit was manufactured in 1991 or 92
The full model number is something like APL 164-6xx but the digits are wiped
off the label.

Remove the X from my reply to address to contact me, I'm in the U.S.

Thanks
WB