We have a Trimark entry system and feel it is adequate for keeping the rig secure. In storage there is nothing of value left inside. The electronics are left there but today those are not worth the hassle of removal for storage at home and then installation for trips.
While we are traveling, that's different but still it is a matter of do we really need great goo gobs of stuff. My jewelry is two watches, the DW has some pieces that can never be replaced and yet she takes them with us because she enjoys wearing them and if they are stolen, well they are still held in memory.
The thing that can never be replaced is the feeling of security. Most people who have lost significant things to thievery are more deeply touched by the feeling of violation than the loss of the material things.
I have never seen a deadbolt lockset that was designed for a 1.125" door, I'm sure they are out there and I'm sure they are bottom of the line. A great deadbolt such as a Baldwin or Medeco can run hundreds and are designed for 1.375" doors but will fit a 1.125" door. What they won't do is make your rig safe they will just make a thief more anxious to see whats inside.
Noise in a campground is probably your best deterrent, a very loud siren or horn blasting away will definitely draw the attention of others. A car horn will just elicit a rude comment about some stupid jerk can't operate his car/truck alarm, however, a very loud and unusual siren with a weird sound will cause someone to look out their window. There are alarms that use voice recording that are addressing the thief and will scare away most thieves and I don't mean a dog barking.
"I travel not to go anywhere, but to go. I travel for travel's sake. The great affair is to go". R. L. Stevenson
David Bishop
2002 Winnebago Adventurer 32V
2009 GMC Canyon
Roadmaster 5000
BrakeBuddy Classic II