Above is a 1917 map of the battle area with Neuve Eglise where 294 Battery was located on left and a modern map showing the same area
View WI Battlefield in a larger map
The 294 SB was located at T21.a.25.75
It is as I suspected - A is top left, .25 across and .75 up, so X marks the spot. Thanks Phil http://1914-1918.invisionzone.com/forums/index.php?showtopic=189114#entry1846812