The most obscure Von Dutch piece of art I've never heard of, the credits for the terrible movie Angels From Hell, and the murals in the bars, and the garage ( I now consider this the most thorough Von Dutch blog on the internet)

From the comments in IMDB reviews:
"Von Dutch" Howards extensive artwork throughout the movie, including the opening credits. Bud Ekins's appearance riding the beautiful Triumph 500 Metisse certainly didn't hurt either!

Von Dutch's artwork, a usual, is Krazy! Check out the full-sized Harley chopper he painted on the barn!

Directed by Bruce Kessler, former race car driver at Le Mans, and team driver for Lance Reventlow's Scarabs, consultation from Sonny Barger

http://www.imdb.com/title/tt0062669/reviews

Was Von Dutch just showing off a chemistry formula? Or being an asshole?
H2 PO3 is DiHydrogen Phosphate (the ion that results from the first ionization of Phosphorous acid) and (NH4)2 C2O4 is Ammonium Oxalate: which is colorless, poisonous crystals.
So, as near as I can figure, this chemistry formula makes phosphoric acid. That stuff is used by Coca Cola to make it's soda have some tangyness