Postsynthetic decoration of the Mn-7, {Mn-III subset of Mn-6(II)}, core with Cd-II in the outer shell to form the next generation Mn13Cd6, {Mn-III subset of(Mn3Mn3II)-Mn-III subset of(Mn6Cd6II)-Cd-II}, core-shell disc was achieved and confirmed by single-crystal X-ray diffraction. The formation of Mn13Cd6 has only been successful with Cd-II and if the Cd salt is added within the first half hour window when the inner Mn-7 has formed. EDX and ICP-AES gave the accurate content and confirm the average found by X-ray diffraction. HR-ESI-MS was even more precise by revealing three prominent molecular species, Mn13Cd6, Mn14Cd5 and Mn15Cd4, having a distribution of metals. The presence of nonmagnetic metal on the periphery reduces the exchange between these clusters as well as the low magnetic moment decreases the dipolar interaction resulting in a paramagnet compared to the ferrimagnetism found for the parent Mn-19, {Mn-III subset of(Mn3Mn3II)-Mn-III subset of Mn-12(II)}, disc. This study opens the way for the syntheses of heterometallic core shell clusters in a controllable fashion.