We do a lot of ink hydro transfer...camo dipping!
You can dip over the factory applied finish, a lot of folks change their camo every time a new pattern hits the market.
Problems that occur....the finish can be scratched off, if you were to drag your firearm behind the truck for several miles! Actually, this type of finish is incredibly tough, not easily scratched and will last for....ever, as long as it was applied correctly.
It is resistant to 95% of all cleaning chemicals, some cocktails will fade, or even lift the finish, but it is very rare! The dipper will advise you of what to steer clear of.
After the firearm is dipped, if completely covered, and again, applied correctly, your firearm will be 100% water proof, no more rust, no more oiling the exterior, just wipe it down with a soft cloth and your good!
Most dipping outfits I know of, or the ones we use for our shops, do a top notch job on the disassembling and reassembling of the firearm. The guy we use the most does an excellent job of this, and his dipping prowess is second to none...he does a lot of big name manufactures dipping, so he has to be doing something right!
Call this outfit up and talk to Don...a fine upstanding gentleman that will do you right!
Check it....
http://www.camo-solutions.com/index.html
Tell him Uncle Mike sent you...well better not, he may run you off! hehehehe
Top notch dipping...top notch gentleman (Don).... excellent retail pricing!