Vernier to Digital height gauge.

[tooly]

Yes I can see it would only mount on the back of the vernier gauge[ I have a Mitutoyo one with the scale on the left] I can see now yours had the vernier scale on the right hand side, this places the digital read out in a more favorable position. There must have been left and right hand available.
I am going to do a conversion on mine and had not thought about the viewabillity of the read out, not so convenient for a right handed person, however I have a remote readout so it will be a bit easier to use.