On standard MM 10/12 fine adjustment is not normally included.  Standard MM 10-US/MM12-US fine adjustment is part of the US attachment.  Occasionally, depending on customers application, but specifically when the point splitting attachment is purchased, it makes sense to add the micrometer fine adjustment option to the standard MM 10/12.

This fine adjustment micrometer is mounted on the right hand side of the machine with a adapter plate.

If your serial number is below 2000 you have a Meteor MM-10/80. If your serial number is between 2000 and 3000 your Model is MM-10/90. All serial number above 4000 are assigned to the Model MM-12.
The above information is important for all chuck and collet related matters. Same type chucks are used for MM-10/90 and MM-12.