I set about looking for some similar fabric. I could not find the exact fabric like the dress is made from, but that was not of utmost importance to me. I just wanted some that was similar. I finally found some fabric at Mood Fabrics described as a Bright Navy/Gray/White/Red Plaid Suiting. The navy in the fabric is actually a bluish-purple. I would link you to the fabric, but it is now sold out. However, I found some that is even a little closer to the Perthshire dress fabric here at Joann.com. I looked for similar patterns and decided that Butterick 6582 -View C would work.
Here is my outfit with my "Perthshire Dress".
Purple turtleneck - Old Navy
Aldo "Iavocone" Booties - Aldo