Sounds like you have it figured out Jenn. Do you have one of the add-a-quarter rulers to use to trim up your seams and keep them uniform?
https://www.amazon.com/CM-Designs-Co.../dp/B003W0PNX4 There are YouTube videos to show how it is used.
If there are no noticeable names on the pattern sheet or anything saying copyright, the copy shop may be good with reducing it for you. Also, I enlarged a pattern and I was able to get an email from the designer giving me her approval. That was several years ago, but the copy shop did accept the email.
I love the Lone Star quilts but hate trying to match up all those seams. I just can't go with the galloping horse idea. I really look forward to seeing yours.