Welcome to Minirider's.
There seem's to be a couple of Thumpstar's and look a like's popping up in Sydney atm
Is that frame alloy ?
Does it have Thumpstar stamped into the frame at the head tube (behind the front number plate), and does the bar clamp have Thumpstar on it?
Can you post some closer pic's of it
And is that a '74 Challenger in the background ?