Hey fozzy, are you sure thats the right way round? if I pushed up on mine with your template it would activate right or left.Mines 90 degrees rotated???
EDIT:you could be right fozzy,I think I remember undoing the four screws and turning it now ,so its easily altered.
bossyman if you follow the link that Quarters kindly posted, the outside holes are the exact size of the 360.There are no inside holes on the 360 like other Happ bases which is why it wont fit your pattern but like I said earlier you could drill your own.