I would somewhat question mounting them with the lock(key) down, it would seem to me water could get in there and cause possible problems. With the lock up, which is how they come from Jayco/Starcraft, you can seal against water better. Plus, as Tunce mentioned, it is easier to latch them.
2013 Starcraft Travel Star 229TB
2011 Jayco X17Z(traded in)
2010 Jayco Jay Series 1207(traded for the 17Z)
2011 Chevrolet Silverado 2500HD Z71 CC 6.0L/3.73
Reese "Pro Series" 800lb Trunnion WDH w/sway control