I am a lefty too. If shooting a gun with the lock on the other side is so wonderful, then why don't all you right handed guys buy left-handed guns to shoot???? Sure would end that problem about resale value, NO?
I recall a day when a very fine rifle and shotgun shooter put my left handed bolt action rifle to his shoulder and looked through the scope. He went to open the bolt to cock the gun, and realized, for the very first time, what we left handed shooters were complaining about, not being able to get left handed guns. I had to show him how to rotate the gun 90 degrees on his shoulder to make the bolt handle available for his right hand to operate. Once he got the hang of it, he was okay. But he was stumped until I showed him how to do it.
I have large hands, and long fingers, so reaching across to cock the hammer on a right handed muzzle loader is not a big inconvenience. My first rifle was right handed. But I shoot better with my left hand gun.