Sorry, I thought I had put the dates in more clearly

I have seen dates given anywhere between 150 BC and 200 AD; given how much the weight can vary, it isn't a stretch to imagine that these may have been made for 200-300 years.
The deformed cranium doesn't mean much; that was a common thing across the entire inhabited world (except for Western/Southern Europe and the core of China) from before recorded history, and continues to this day in small pockets.
What few clues we have about the dating:
- The legend is almost exclusively in Greek, not Bactrian. That probably pins the inscribed coins to before the reign of Kanishka (i.e. 150 AD)
- The portraiture is refined and, on early coins, in high relief; a calling card of a Greek-trained celator.
- The miniscule ω was not commonly used on Greek coins until about 100 BC.
- The "soldier" (I've heard it suggested he may be Pharro) is in a pretty distinctive Kushan outfit
- It's impossible to deny the parallels in portraiture to the Kushan king "Heraios":