GG is that one person that help to induce GAS for things you never knew existed.
I'd say it's as much of a Pignose clone as a sandwich is a clone of another sandwich?
It is a portable amp, roughly the same size, construction is quite different, single porky pig knob vs having a tone control, strange cells and the board mounted up high.
The original Pignoses sound surprisingly good. I have one, and tone wise, it rivals any amp that's got the goods. It's got warm tone, a bit of rasp, a stupid amount of volume, easy to carry, look neat, invented by Terry Kath, it's an amazing piece of gear from America's golden age of gear, but an original Colorsound Mighty Atom is prob worth several times what an original Pignose is worth.
Not sure the 1st year of the Pignose, or this, but obviously the early ones have 60's styling and the later ones 70's.