I'm actually surprised to read this. I've been full timing all over the continent for about 2 1/2 years.
I have pins with clips holding my fastguns closed. That's it. No locks.
I don't even go to campgrounds. I park anywhere and everywhere. New York City, Miami, sketchy small meth type towns, Los Angeles, El Paso, Coachella, Detroit, San Diego, San Francisco, LA suburbs, San Fernando Valley, West Covina, Santa Clarita, Orange County, Burning Man, Denver,Boise, you name it, I've parked overnight in it with this setup. Never even in a secure campground.
I think you're overly concerned with fastgun theft. No one even knows what they are or notices them except other TC owners.
I also doubt anyone is stealing a TC/truck combo. They stand out like crazy and are impossible to make a getaway from law enforcement in.
Stealing the TC by itself is literally impossible without a forklift specially designed to have long tines to support it.
Mine has been on the streets about 900 nights now. Only security issue was a truck driver trying to break in in Ottawa Canada. He gave up after he found the door was locked.
