Is the MTW / Article Series compatible with AEG mags / grips / stocks / rails etc?

The MTW is designed to be a modular platform with highly interchangeable parts within the MTW-Spec family, with real steel firearms, and with AEGs when possible.

You can find a full breakdown of parts compatibility here: https://www.wolverineairsoft.com/knowledgebase/mtw-spec-parts-compatibility