I have had mine in my hand, and can tell it is a pretty compact device. I can't imagine there would be any room to drill and tap for a zerk. The very act may destroy it.
Most of these types of devices are lubed for life.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.