In the cad drawing by J de Waal he puts a dimension of 2 and 1/16" from the center line of the cylinder to the first 2 of 4 holes for the locating pins for the support frame.
This dimension should 2" as per Bob's drawing. The 2 and 1/16 is to the first pair of tapped holes which are on 1" center's and are for the support frame brackets.