Laboratory G, the Mercury Address and the Register Ratio G31

A short geometric note comparing the laboratory value of Newton's gravitational constant $G$, the Mercury orbital address (1/aMerc)^2, and the register ratio G31=31^2/144. The relative difference between the two geometric quantities is 0.00085%, placing both numbers within the same numerical range as empirical G determinations. The correspondence is recorded as a pure geometric fact inside the UKF address language.