The one at the bottom is no longer manufactured. they stopped making the one at the bottom a long time ago. The one at the bottom was BMR air stop arm. The one at the bottom is the illegal slow sign.
Oringinal 1946 red octagonal stop sign
1988 caution plate saying "IF-SAFE STOP THEN-GO" instead of a stop sign (no longer in style)
They stopped making this one a long time ago. This one is no longer legal, no longer manufactured, and no longer used on school buses or ice cream trucks also this one is no longer in style. Now ice cream trucks uses a yellow one like this that says Children Slow Crossing. They stopped making this one in 2002. So this one is a school bus part or an ice cream truck part that is no longer in style. They don't make this one anymore. This one was BMR air stop arm (the illegal slow sign)