Horsepower

Cel

A batch of animation cels appeared in a recent eBay auction and the majority appear to come from Horsepower.

Cel

Horsepower

Crown Agent

Voyager

Cel

Chief Pawnie

There are only a few episodes with Doc and Niko wearing hats, and Niko with shoulder strap is even rare. Dave Morris has a cel description at ComicArtFans.com has a description of "Nico and Doc, on a non-matching background."

Reference cel with non-GR background

Doc & Niko with hats, Niko with shoulder strap and odd eyes