Your plant is very similar to mine. The difference is with the central spines. Your looks to have 2 darker, short, which is in accordance with the description of tlalocii. Mine looks to have no central spines.
M. grandinosa is described as having no centrals.
But, if indeed my plant is L1116, its location (San Juan Bautista Cuicatlan) is 28km north of where M. grandinosa was found (San Juan de los Cues). I guess that might not be significant.
Maybe we'll see in some more years, as tlalocii is supposed to stay single, whereas grandinosa offsets like crucigera.