I'm a new EM15 owner, and while I've distilled a lot of excellent info from @dfkrug 's epic thread, I wanted to just publish a pile of info specific to the Diggit EM15s.
OEM is LeKing (Link: Mini Excavator Mfrs and Suppliers-Shandong LeKing Machinery) and OEM model is "Mini Excavator-KV13Plus"...