Cleaning Mark on Lenses

With older single coated lenses, many times I have seen slight cleaning marks on the outer lens surface. Does this effect optical quality ? I have read of technology to apply new coatings to the lens surface. When is re-coating such a lens worth the effort from both a practical and economic point of view ?

In most instances the cleaning marks will have no noticable effects. I dont know the cost of recoating a lens, or who would do a good job of it. They would definately need to know how to put it back together properly. From an economic point of view, I would say if the cost is getting close to the cost of a used modern multicoated optic, its not worth it.

Well, here's a story. Last year I bought an old 10" Wide Field Ektar for my 8x10 Deardorff that had some "polishing marks" on it. I was tapped out after buying the camera and my prime lens, a 14" Commercial Ektar, and was eager to save the $200 or $300 off the price of an optic in better condition. I was concerned about the marks but figured what the hell. Recently I started a new series of studio nudes (http://www.ravenvision.com/rvapeterflowerpetals.htm) and the studio I was using was too small for the 14", so I switched to the 10". When I processed the negs I discovered, much to my great joy, the the "polishing marks" had provided me with a beautiful softening effect, a gorgeous halo around my models' bodies, further accentuated by the soft light I was using. Had I spent the extra money for the "better" lens, I would have missed this effect, which provided me exactly the look I was striving for!