I kept mine fairly simple. I added a Bushnell red dot and mounted an ESEE Izula on the stock.
I found a pouch that would slip onto the knife handle that has a few survival items, some extra ammo and spare batteries for the red dot.
I just need to get a new thread protector and I should be done. Although I've been thinking about replacing the side and bottom rails with some black canvas micarta.
Best little pack/survival rifle I've ever owned and fits perfectly in the hydration pocket of my backpack. Perfect for getting a few grouse or rabbits of opportunity while big game hunting.