Seems there is a new Z axis digital read out on the Bridgeport mill. Thanks Tim Bene, I know because I saw him in the process of installing it Sunday evening.
Last night David Kessinger and myself used a test gauge to examine the accuracy of the new z axis digital read out and the hand crank micrometer for the z axis lift (knee lift). It appears that both the knee lift micrometer wheel and the new digital read out are within about 1/2% or so of the indication given on the test gauge for a 100 mill travel challenge. So this is a good instrument. Makes it a bit more difficult to set/adjust the quill stop but likely overall utility of the mill has been advanced.
Thanks again for being such an excellent member,