Block Conundrum

Ooooh, I HAVE been away a while! I have done practially no sewing at all since New Year (unless you imclude fixing the hanging hook on my coat!) but I have had great intentions to start on my next quilt.

Last night I found the pattern I had saved for my Curio quilt and was ready to start slicing fabric, but I'm just not keen on it any more. After much research, I decided that Curio looks best in really detailed quilts and I found one that I think I will end up copying, but I am not quite sure how to do it.

My inspiration is here at Bellet Blog and the following picture is her own quilt.

I love the concentric circle spiderweb with a string pieced diamond shape between. It looks like a mixture between a Spiderweb and a Rocky Road to Kansas quilt. But the bit I can't figure out is how to draw the pattern pieces.

I have been researching Spiderweb blocks and the best I have found is at A La Mode which was sent to me by Kris, but the problem I have is that at this step;

(photograph from A La Mode's tutorial)

I need to split it into 3 seperate blocks (the left and right hand triangles would form segments of 2 spiderwebs and the central kite would be a quarter of a rocky road) so that I can make strings for each segment.

but what do I do about seam allowances? The tutorial has already accounted for seam allowances around the outside of the complete triangle (I presume) so do I just add 1/4inch along each side of the 2 blue lines for each of the pieces?

Advice needed as I think I fried my brain trying to do this last night and I really want to get started!

J x

EDIT: thank you Laura, my package arrived last night and it looks perfect. I can't wait to get started now! X