Methods for forming an insulative body of an implantable medical device connector module assembly employ an injection molding process, whereby first and second shots of insulative material form core and an overlay portions, respectively. In some methods, a panel portion of an electrical component is mounted between opposing surfaces of a mold such that a finger-like portion of the component extends into a cavity of the mold, with a first side thereof touching another surface of the mold and a second, opposite side exposed within the cavity; following first shot injection, the core portion captures the finger-like portion in relatively rigid relation thereto. When two types of connector bores are formed, a color indicator may be engaged with a feature of the core portion that is located in proximity to a connector bore of the first type, and then the overlay portion is formed over the indicator.