The Manson (Brownell) W/T gauge is hands-down more portable than a weighted-base table top model and easier to manipulate to achieve repeatable results with the Oscar Gaddy-recommmended method of use. When I built mine (tuning fork similar to Manson w/ addition of "Gaddy spring") I found a British tuning fork model for sale on EBay which had a second, sliding yoke obviously intended to optimize rigidity at shallow depth measurement but also retain 15-16" depth capability. With arm protrusion limited to 6 or even 9" from the yoke, a tuning fork model has no more deflection than the Louis "Boremaster" caliper. For the price of a Harbour Freight dial indy (15$) and a few bits of steel and aluminum, the tuning fork CAN BE a precision measuring instrument IMO. The Skeets bore mics work for me. The cumbersome "combo" gauge is the last thing I would invest in as is not much more than a straitedge with a machinist's bevel on the end.
jack
