The first three are:Little Wars by H. G. Wells (the 1970 Arms and Armour Press reprint with a forward by one of the deans of science fiction, Isaac Asimov)
The aforementioned Wargames Tactics by Charles Grant (1979 Hippocrene publication)
Charge! Or How to Play War Games by Brigadier Peter Young and Lt. Col. J. P. Lawford (1967 Morgan-Grampian publication)

The next three are:
Scenarios for Wargamers by Charles Stewart Grant (a WRG 1st edition publication)
Setting Up a Wargames Campaign by Tony Bath (the 1978 WRG 2nd edition)
Programmed Wargames Scenarios by Charles Stewart Grant (a WRG 1st edition publication)
I'm sure I have a few others, but these are some of what I consider basic "Old School" wargaming publications.
