TrackMaster Bert & Arry Chinese knockoffs

[Super]

I am now curious to the their faces. In the real Bert and Arry don't they each have a different expression? If so what about the Chinese copies...are they different? If I remember correctly isn't Diesels face part of the shells mold and can not be removed? Are the copy cats removable? Also the mold of Paxton also looks to be a match for the copy cats in switch position and grates on top.