Sulzer Mixpac Specialty Tools Huh? What Are These?

Description

Hello. These 4 tools are contained in a Sulzer Mixpac plastic bag. The person who I got it from knew nothing about them...neither do I. How about you? Havent seen them anywhere. 4 brass pieces, 3 like plug gages. One screws into a nice chuck that adjusts down to zero.Says BDM NY on the plugs. Thanks.  DS