Terri-

The cylinder rotation line is called just that. (Sometimes called a "turn line.") It comes from the cylinder bolt dragging on the cylinder as it rotates, and I don't think I've ever seen a revolver that didn't have it if used much, although a well-timed cylinder system will show less evidence of it.

The cylinder (NOT the chamber) is the big round thing that holds the CTGS. ((Cartridges) This cylinder contains six chambers, which hold the ammunition. (An autoloading/automatic pistol has just one chamber, which is part of the barrel.)

Pitting is the tiny rusty holes left in steel when rusting is allowed to progress to that point. Yes, it looks like rough spots. If it isn't very deep, a complete professional refinish job may be able to remove it, or an engraver can sometimes incorporate patterns in the engraving to delete it. Neither refinishing or engraving is cheap, if well done.

This gun is not in good enough condition to interest a collector, as so many were made. I believe that it is the most common of all high quality revolvers ever produced. As a shooter, it is too old to use with high velocity cartridges, called Plus P. And blued steel rusts if not given frequent cleaning and oiling, as you can see.

I'd put your money into a more modern stainless steel version of this gun, called Model 64, introduced about 1970 and made into the 1990's without the objectionable lock feature of later guns. It is acceptable for Plus P use when you want the added power, which is still not a lot, as compared to the .357 Magnum. But recoil and muzzle blast with the .38 are less, and many women prefer not to have to learn to handle the .357.

Unless an older M&P .38 like this one is in exceptional condition, it will not interest collectors and the only reason for anyone else to buy such a gun is a nostalgic interest in the period when they were made, or because the price is especially low. Even in the latter case, I'd save up and buy a newer gun.

Personally, I'd never buy a gun with any pitting. It shows that poor care was taken of it, and that may extend to the internal mechanism. And rust and pitting look awful, and are hard to stop, once begun. Think of pitting as bad acne as applied to firearms.