I don't know much about this, it came out of my dad's garage. If he used any, it was not much as the can is nearly full of powder. You would mix only what you needed, using cold water. Other than a dent in the can where the "D" and "W" is on the front, the can seems to be in great used shape. I didn't have luck finding the patent numbers, but as this doesn't have a zip code printed, and my dad picked up most of this type of products in the 1950's and 1960's, I think it dates to about that time.
Shipping quoted is via either Priority Mail or Parcel Select, with Priority being fully insured for your purchase price.
I try to ship within 24 hours of receipt of your PayPal payment.
To cut down on shipping time, at this time I'll only be accepting PayPal.
Returns & exchanges
I don't try to be an expert in any particular field. I will try to describe an item to the best of my ability. If you an item to be other than what I've described, then I will be happy to refund your money upon return of same item.