Well, copies of anything to do with Gregg Shorthand seem to be more scarce than hen's teeth here in Australia but I have managed to track down a copy of Simplified Gregg (published by McGraw-Hill). It's now on order, as all the publishing companies seem to have closed down for a month over Christmas-New Year. I should receive my copy in early-to-mid-January. In the meantime I've downloaded a copy of the basic outlines for all the consonants and vowels so that I can start learning something at least.
One question I have straight away, however, is how the Gregg system handles the differing regional accents that occur within the USA. Is there an "accepted' correct pronunciation - and therefore Gregg outline - for all U.S. of A. words (as occurs in British English), or do people in different parts of the country write their own versions of Gregg shorthand according to how they hear the word pronounced by others, or by how they pronounce it themselves?