Goater, check Sheffield for the unground O1 in bar or sheared sheet. Much cheaper than P&G. Also contact Cincinnati Tool Steel Company. NJSB gets some of his steel from them I happen to know for a fact. Their shipping is $20 flat fee, one pound or twenty+. Thinnest L6 is 3/8" sheared sheet. O1 is thinner, but they have several locations and not every location carries everything, but they have some good "from the book" HT data too. Having forged L6 I can tell you it makes great axes. They have it in 1/2" plate too, cut to size.
http://www.cintool.com/page.asp?PageID=2
http://www.sheffieldsupply.com/SUPPLYCAT.pdf