Your welcome. Here is anothert way to do it. I know some will not take teh time to do all of this, that they wanted a 12 1/2" block from the beginning. Their choice.
Ok, here goes:
Click on Template A
Left click on File
Go to Print Preview
On that ribbon, go to the box that says "Shrink to fit"
Click on the down arrow
Scroll to Custom, click
Type in 130% as your starting point, hit Enter
Place your cursor on the Printer on the same ribbon
Left click
Printer box comes up. Be sure you only print one for now. Repeat steps for Template B.
Cut out templates, match up 1/4" seams, and measure. Should be somewhere in the vicinity of 12 1/2" unfinished. If not, adjust the percentage either up or down by only a few % to get the size you want. Once you get the hang of this, it only takes a few moments. Most will find this method aggravating. Be patient, it is worth it. This is how I take templates and increase/decrease, all the time.
You will notice that some of the template is cutoff. Don't panic. Study it and decide how to best copy what you need. Really not that hard.
I am on my way to school and will be home later this eve. If you have any questions, let me know. Don't make it harder than it is.