I also own a Model 38. It's size and shape makes it a good candidate for pocket carry. I would recommend against +P ammo. The gun could probably take a little but the frame would likely stretch if you shot very much. I've got splotches on mine, too. It just comes with actually carrying this pistol.
If you want to retouch it, go ahead. I think some folks here get overly stressed when they hear of someone wanting to touch up or modify a gun that isn't all that valuable as a collectible.