This is a awesome picture. I'm not sure I could cut it.

I have just the pattern for you. I use this for all pictoral prints that I find. It is easy and can be made an many sizes. The only trick is in the cutting. Read twice before cutting anything. The Pattern is Prairie Window. Check it out at www.quiltwoman.com or www.make-it-easy.com

I would cut a square opening in paper or cardboard and see how large a block it would require to get the motifs and then use the large blocks as a focal Might just put sashing around it.

Several years ago I used a jungle print that was printed in large motifs. I just cut it into squares and did an attic window type sashing around it. I didn't try and cut specific motifs but just let the cut fall where it would.
You almost don't know that it was cut without fussy cutting from one fabric. I made mock attic window sashing in which the mitre wasn't cut and stitched but folded at the corner. It was very easy to make and quick.

Check out panel print quilt designs to see how they spaced blocks and set them off with different sashings/blocks. Random sized blocks would be interesting. I like your idea of batiks that go with your sepia print. I'd use a see through template to fussy cut fabric, selecting area you want to highlight. You will lose some scene as you cut out and focus on a section-can't be helped. Very unusual fabric and I'll bet your FIL will love the quilt.

I too would make it into a center panel. Lots of great ideas here!