What if you used a moderately-narrow, brown border first - to frame your beautiful work, and THEN put the original fabric as a slightly larger border and then bind in a thin brown binding ....
I love to see the original fabric along side the composite pieces; wouldn't want to have to turn it over to get the impact .... Someone not familiar with the technique would lose the total intricacy/concept of the varied blocks ... and the workmanship involved.
Just one opinion .... ;)