After much procrastination (and some sketching), looking at various guns, etc...and some more procrastination, I think I finally found a good combination of what will fit the gun and what I actually have a chance of creating with a reasonable level of success.
First, I was looking at this:
Option A
A quick photoshop on top of the stock picture:
With some tweaking, I think it could work and stylistic, is fairly close.
Then I took a look at option B:
This one I did a rough sketch and I'm a lot more confident that I can pull that off than option A.
I see flaws now that the pictures are posted next to eachother, but I still think I can make that design work.
I've held off working on the gun until I had this sorted out, but I'm now happy enough that I can finalize the shaping, while I work out this design.