I think this is the oldest Nelson Oil Based Paint I’ve come across. It mentions the Nelspot 707 specifically which means the can likely date from 1960 to 1970.
The back of the blue can does have a stamp of 7-83 but I don’t think that’s the date since by that time Nelson wouldn’t have been selling the Nelspot 707 and would have already to moved to selling the Nelspot 007 (or Quick Splotch?). And the paint at that time would have likely been the aluminum tubes (with the cardboard oil based Super Spot tubes sold between the tin cans and the aluminum tubes).
I purchased these two tin cans along with a Nelspot 707 from a seller on ebay in 2009. I paid around 13 dollars for these cans before shipping (the 707 was not included in that 13 dollars!).
The exterior of the cans show some rust and the paint has been combined into the yellow can. The pigment and the oil in the actual paintballs are completely separated and the paint is pretty hard shelled. If I ever get a 707 to stop leaking I’ll have to test this paint out.
I believe the tin Super Spot paint cans predate the cardboard tubes because the tin cans mention only the 707 and the cardboard Super Spot tubes mention both the 007 and the 707. Find more info on the carboard tubes of nelson paint here: