So I'm guessing this is the 3rd Generation of Speedways that existed in the 60s and 70s. It feels like these looks more similar to the 1st generation/Trenton Potteries Speedways in appearance.
They're one of my favorites and I can't help but flush them a second time.
The Stanton here also doesn't disappoint with a pretty solid flush.
The Santons all seem to behave differently. One with a weak flush, the next with a long double flush (sticky worn out valves), and the last one pretty average (nothing wrong with that).