Okay, it's 1:40 am and I have a sneaking suspicion about this case.
I'm wondering if this scammer isn't some 20 something kid who had been using Dad's credit card (unbeknownst to Dad) to fund his PayPal account while he bought up knives he liked. After all, he did express concern about you calling his parent's house and he comes across in his emails like an immature little jerk.
Dad found charges on his credit card going to a PayPal account, had never set up a PayPal account (gasp!) so he asked his cc company for a chargeback as he thinks someone must have stolen his cc info and set up a fraudulent PayPal account! He has no idea that sonny boy has been using the credit card funded PayPal account to feed his sharp, pointy thing addiction and that all those charges to his credit card are from Jr.'s knife purchases.
Just my wild out-in-left-field why-am-I-still-awake crazy theory on this after reading through the thread. You may point and laugh now.
Seriously, though, Eric, I hope this is all resolved for you soon and in your favor.