All four throwers are visible here and the knobs look unpainted on all four.
This is my theory on the "Super" Hero Thrower. The thrower was modified after principal shooting and the scrolling bargraph was either added in or switched on (depending on if you believe all throwers had the same electronics). The thrower was probably beat up quite a bit at this point, so someone decided to repaint it. However, they didn't bother to remove the labels or the knobs, covering them in paint. Then the shot we see in the movie was filmed by the
secondary unit, as shots like this typically would be, and the person operating the thrower in this shot is not any of the principal actors.
So as I see it:
- The insert close-up shot of the thrower was almost certainly shot at a different time, without the actors, by a different camera unit
The Super Hero Thrower, so far, cannot be clearly proven to be seen anywhere else in the movie
There is no evidence that the Super Hero Thrower was a 5th prop in addition to the 4 heroes.
To me, this evidence supports the theory that the "Super" Hero Thrower was a random thrower pulled into the shop and modified between principal and secondary shooting.
Don't talk to anyone. Don't touch anything, don't do anything, don't interact with anyone, and try not to look at anything.