Sorry for not coming back! :-)
I've been a very busy little chicken.
What I ended up doing was printing out the templates, measuring them against the square, and whacking off the ends. So I could pile up all my triangles, whack off the ends, and they match the squares perfectly.
No folding to find the centres, no mucking around measuring or pinning. It was excellent!
Shame the blimmen block didn't go well though! LOL This was supposed to be for the blue and yellow swap, and it's a full 1/8th too short. Not sure if I'll put it aside and not bother, or if I'll try and spray it and stretch it to fit.
Diamond in a square. :-) I was having trouble getting the triangles on straight quickly.
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The whole block.
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