What is this? It purports to be a semis. Assuming it is authentic (I am not so sure but I won’t condemn it just yet), it is completely anomalous. By the time of Commodus, Rome no longer made semisses. The dated reverse is also atypical of semisses. The size is about right for a denarius but a fouree of a denarius seems unlikely as surely no forger would put SC on the reverse. So what is this thing or maybe what is it supposed to be? https://www.ebay.com/itm/COMODO-COM...920298?hash=item3d5882022a:g:NAwAAOSwbe5ad3lg
The style is all wrong to be official. I don't recall seeing barbarous asses from Commodus but they exist before and after so there is no reason it could not be. In the end, you need to decide if the patina is old or new.
Odd as it is, it seems most Ae denominations were imitated. I have several quite nice imitative quadrantes, which feel like a lot of work for a very low value denomination. The size of this though (21 mm, 4.24 g) appears too small to be a plausible as. The patina doesn’t give me a very good feeling. Assuming it is ancient, you are probably right that is an imitative as. If not ancient, someone didn’t do their homework...
There is a difference between ancient counterfeits and 'barbarous' coins. Counterfeits were meant to fool everyone, and as such your coin does not fall into that category. Barbarous coins however are a different beast. They can take many forms from simple stick figures to near perfect copies. I would suggest yours is barbarous, meant to be used where it was made, likely out of necessity due to a lack of local coinage. I have no problems with the patina as it appears in your photo. I dont collect them per se, but I do have this Claudius Sestertius:
