I started by grading the pattern up a few sizes and I plan to make the muslin out of a bed sheet a purchased at a thrift store a few months ago ( you can see it right above the pattern).
Here is the Grading with Pattern and Sheet
Since I thought I would need more than just a bit added on the sides of this pattern I decided that I would try a new (to me) technique of slashing the pattern and adding the inches in between. Hope fully this will work. Since this is such a simple pattern I think it will come out fine (knock on wood). I am hoping this will be a success as I get very frustrated with having nothing to show for my time in the last 2 muslins I made. Hopefully I will show you some results by the end of next week end. Take Care All