Une inscription de Cantabrie (?): fiscalité tétrarchique ou centuriation ?

An inscription which we know to have been sold in the area of Santander and which has now disappeared poses an enigma. The abbreviations K and IVG, which strongly evoke the Tetrachic fiscality, are carved on this "bifrons" stone of uncertain origin (however probably from the same area). It would have been a 'scoop' for the Western part of the Empire. However, a more systematic study of the text and a comparison with the known epigraphic tax registers forbid such an interpretation, especially in view of the inadequate numbers which it reports, not to mention the dubious function of such a stone in a fiscal hypothesis. Another explanation would be to relate it to centuriation : could this stone have located a parcel of land by giving two of its angles as orthogonally projected on two reference-axes? J.-P. Vallat ultimately advances a "gromatic" solution of the enigma set by the text and its numbers.