FYI, here's the PDF of the section of the service manual that details the update. Seems that any engine in the USA will likely have the extra oil spray nozzle, unless you got one of the first couple dozen that rolled off the line (not likely):
http://www.meimann.com/docs/mercedes/OM603_vac_pump_mod.pdf
(The last 2 pages show how to adjust the IP max speed governor and full load fuel delivery, in case you're feeling like causing trouble with your IP!)
Regards,