Well it's all going terribly well here.
I veh veh carefully did all my calculations
(I'm a scientist you know) then I did them all again then I did some hard sums and some adding and subtracting and then set about making my HST squares.
Lovely!
I took my ruler and my rotary cutter and I removed a scant quarter off every single side of every single %^&^% square! I'm just glad I'm not in charge of anything important!
Oh wait.....
Now they look lovely anyway....though smaller.