Happy to post pix of a tuning fork-type gauge in use suspended from overhead but can't get access to P-bucket due to some BBBSSS about six character passwords. Some of us here, including JL and myself, employ the gauge in the vertical orientation based on the experience and recommendations of the late Oscar Gaddy regarding methods to reduce manipulation-induced error. Some of us also have a piano wire spring (or spring-actuated brass lever) opposite the anvil ball on the internal "tyne" (sic) of the fork, intended to hold the anvil in contact with barrel wall by pushing against opposite wall. This is, or used to be, called the "Gaddy modification".
I've arrived at the point where I don't think it matters all that much whether you keep your sox up with garters or with new-fangled elastic. Certainly, the extension past the anvil on the internal rod of the Hosford model (and on AM's "truth" gauge presumably) is important in that it allows Mike and Hosford to zero their gauge while accounting for gravitational deflection of cantilevered weight. Mike's photo of that vital procedure is very clear for a gauge in which the anvil is a bearing ball located away from the bitter end of the internal rod. This is almost impossible to do with a rod on which the anvil or contact point for the gauge plunger is a turned or screwed-on swelling at the very end of the rod.
Pix of mine later mebbe.
jack
