[Carl n Susan]

While true that most RVers have a CH751 key that fits your lock, they really aren't the ones you need to be concerned about. Key or not, those doors pop open with just a screw driver. I tend to leave the doors unlocked when camping to avoid some thief, bent on getting in, doing more damage with their screw driver. But if it makes you more comfortable to change the locks, there has been lots of discussion here in the past (before Montana quit using the CH751 keyed locks). A quick Search will uncover a treasure chest of postings. One member had a brand new set of tubular replacement locks which he was selling last year. Perhaps he still has them.

Here is one, of many, posts I found which is pertinent. Baggage Locks

As for adding struts, do a Search on those puppies. They were a problem initially due to the screws pulling out of the flimsy wood. The addition of a larger metal base plate, cemented to the door and larger screws seems to be the solution which even Montana uses today.