Dear Barcah2001,
First, sorry, but there's not a chance of GTSTE being ready "next month," or probably even this year.
While blind play-testing has been completed over the last couple of years, and virtually all research and compilation of materials has been completed, the final ms has yet to be launched.
This is entirely due to the pressures to create more short-term projects that can spur sales immediately, and this absorbs most of my time over the last few years. It doesn't help that several other books are in development, and the foray into 54mm resin figures is a major--though vital!--distraction.
I can say the final work will contain complete OB's for most battles, detailed period maps, full lists of all US Regular and Volunteer Units which served, and as much information as possible on the Mexican Army.
The game will also include three Game Card Decks used to determine order of movement by Brigade, the number of orders a given Commander may issue in the coming turn, and random events and effects.
A number of other useful card stock markers will be included, eliminating the need for written record keeping.
If you're interested, E-mail me at TVAG@att.net and I can send you an article on the ground scales and mounting rules that may prove interesting generally, as well as considerations of figures to units and more.
I know I said GTSTE would be out by now (indeed, a year or more back), but I've already put years into it and have every intention to bring it to print ASAP. Once Andrew Preziosi's monumental "Sikh Wars Resource Book," and the Campaigns volume for "Funny Little Wars" are in print (at least one this year), then the target for tonight is GTSTE.
Please feel free to prod me and rattle my cage any time!
It's knowing that Gents like yourself are still interested in a proper, from the ground up, rules set dedicated to this remarkable subject.
TVAG