Antique Mills 10 cent Slot Machine with bonus payout

If I had to guess, I'd say late 1930's, but I'm not an expert. The machine is in excellent condition, with a full metal back door and lock and key. Everything works EXCEPT the large payouts e. Cherry wins pay, but larger ones do not...

I'm not sure if it is a coin jam or another problem, but since it is all mechanical it should be easy to diagnose and fix. Priced to sell with no reserve.