I would also consider just piecing the center diamonds and then attaching the long strips.

It would be a lot easier to handle this way and no y-seams -

the OP said she wanted to avoid extra seams -

I played around with the Y seams last night and was thinking that the way you show it here might be my best way. It's not so bad because I won't be cutting up the diamonds which Is what I didn't want to do. So with all this said, I really think joining it at that point for the long straight sides will not be a problem.

Again thanks.

ditto ....... and am looking forward to seeing what the quilt is!

We should have held out, and not given any help til we saw the quilt! (Kidding! :))

here's the middle part of it
http://www.quiltingboard.com/t-162343-1.htm

Bingo - exactly what I would do.

I would get someone else to do it ROFL...I am just a "baby quilter" :)

LOL so is that an offer I just heard??? LOL Why thank you so much, when will you be available? LOL

cut some more pieces out of scrap fabrics and practice sewing them together. then try the good ones you cut for the border.

I would start in the middle, Black ) then sew top and then bottom (dark orange) then add the the middle bottom and then top. Pretty much like when you sew diamond pattern.

Check out Ruth McDowells technique for piecing. It uses freezer paper but it is not paper pieced. You would simply trace the pieces onto freezer paper, iron them to the wrong side of the fabric, cut them out using a rotary cutter and ruler to precisely add a 1/4 inch seam allowance and then sew. Mark the pattern at intersections where you have y-seams with ticks and match them up. It should go together smoothly.