I think you are about right age wise - my bet would be 22 years old.
There are different iterations of the PT motor. From 84 - 98ish they were much better at updating the 'look' of the motor than anything else. That cowl came out in the mid 90s and was used through early 00's. Other designs were also used.
Back to the motors themselves, the main changes were transfer port size in the early days - motors being known by v35, v40 up to v50 or v55 for commercial models.
Around the time of yours they released the VSX motor - several changes to exhaust, porting, intake manifold and a clearly larger snorkel.
Later iterations included the ecotorque ve and vex motors - these are the only ones that feel down on power due to emissions strangulation. Many were governed down to 2700 rpm for emissions and noise reduction. Your garden variety briggs and stratton runs 3200 rpm. at 2700rpm a pt really isn't on its 'powerband'. Will mow fine but give up sooner in the thick stuff than an older model.
When your mower came out, there wasn't much to discern a corvette from a mustang except mustang will usually be an alloy deck and higher spec. you could get corvettes all the way down to steel deck 2 blade catch only (as you can today). Probably victa hedging their bets -corvette for GM fans and mustang for ford guys.
I have seen many a mustang look identical to yours
The main modern difference between modern mustang and corvette is the corvette uses a steel base while the mustang uses alloy
