I did one and used Aircraft Stripper to remove the camo, then applied rust paint, 2 coats of krylon tan and 2 coats of clear matte sealer meant for waterproofing patio stones.
When i lay it on rocks the paint does scrape off in places, if I paint it again might try a different sealer, something tougher if its available. It might also not be tough because I only cured it next to wood stove not out in the sun in the summer heat.
couple of the scrapes on receiver
"The old school hunters shoot what they shoot and kill as many as they always have, the newbies have their 3.5."