The reverse is, as you observed, is of a much higher level of die engraving compared to the reverse, but that happens quite often with denarii and other denominations. The reverse is crude and it is possible I suppose that there might be an over-strike: the centering is off and the fields are quite irregular. There's nothing that really sticks out, such as a letter or design element from the original reverse, but the absence of these signs do not mean there is no overstrike, it really is just a muddle, as is quite often the case with these hammer-struck coins that are nearly 2,000 years old. If someone were to overstrike just the reverse, I am not sure how that would be accomplished without affecting the obverse. In order to create a decent strike, the flan needed to be heated to a considerable temperature, so surely there would be signs of that on the obverse. I don't know. Maybe this coin is a modern effort to create something exotic, but it seems that someone went to considerable trouble to achieve this, but I suppose such as creation is having the desired effect: a coin that people are talking about. Another scenario: Could someone at the Laodicea mint have created this mule? Or, could someone at the mint in Rome have done this? The coin weighs 2.6 grams, which I assume is within the correct range but definitely on the light side. As for the corrosion, yes, it can indeed be artificially introduced with acid, but there are also some deposits on the reverse, along with the corrosion. Again, I guess that could be simulated by a clever forger. Anyways, I think, when weighing the condition of the coin and its odd mixing of reverse and obverse, that it is not from a mint, but instead a contemporary imitation or fake that was not meant to be scrutinized too closely.