bluski if you are going to be away for an extended period I would take the wheels off for piece of mind. Unfortunately, like has already been said, you can't do anything to stop a determined thief. But having a home built should help. I would think that a manufactured unit that is 1 of a thousand would be a better target.
I keep mine in a garage at home and when in use, the only time I worry about it is when I am hiking or biking and leaving it in a remote campsite all day. Then I use a heavy Brinks lock and high grade chain through a wheel and around a spring. The chain runs through an old bike tire tube so it doesn't scratch everything up. Hopefully that is enough to stop a crime of opportunity.