If you find a Dry-Cleaner in your area with a seamstress, or tailor, in the store, you could take the H.A.W.G. in and have a small pack cover made to fit. A small amount of cloth and a bit of elastic won't cost you much and it could be made for you in about five minutes. No need for paint, velcro or carabiners, and you can keep it water repellent by spraying it with
Tectron Wet Guard - Aerosol or
Tectron Wet Guard - Pump or by using a wash-in type if you use a nylon or Gore-Tex fabric.