IFRA issued Oakmoss in 1988 and restricted "Oakmoss Absolute" to 0.6% final product. During 1989, the same happened on concrete oakmoss.
1991: same 0.6% restriction for Treemoss
1997: further restriction (both mosses) to 0.1% final product
2001 : 0.1% limit only for DHA acid in the raw material; it's the main responsible for sensitization.
2008: Mosses extracts must have a very low quantity of Atranol and similar substances
.....If you want a flood of Oakmoss, it's better to find something before 1988 :)