Is this the label? That's good old fashioned enamel.
Buy some Enamel Reducer for industrial or farm enamel and you'll be spot on.
(Not Acrylic enamel reducer or urethane reducer...you want Enamel Reducer)
I know that Delstar acylic enamel would go "seedy" after a few yrs on the shelf...this means billions of minute particles like poppy seeds would pass through the cone filter and appear in the final paint job. I don't recall that problem with enamel but really haven't sprayed it much to know because Delstar & Centari were the "big shots" in my painting yrs.
Maybe your local hardware could put it on the shaker machine.
You can't get closer to original than enamel and it's worth a shot.
PS : don't forget enamel "runs well"...so pick a hot day to spray
