The company that brought out this set did NOTHING to clean it. The worse part is the opening credits that are covered in black splodges from the obviously dirty tapes. All the company had to do was spend a little time cleaning one set of titles and apply them to all the episodes, a quick and easy thing to do it. But no, instead we are treated to the same black marks of dirt over the credits in the same places for each episode. You would think that they copied the dirtiest credits!
Simply Media went for the cheap option - buy a half remembered series (the more obscure the cheaper) and copy to DVD, then sell a product not worth even 10p. Modern video cleaning technology is cheap, quick, and easily available so there cannot be any excuses. In the case of this set even a damp cloth would have removed the dirt and improved things 100%.
I had to return this set as I was initially convinced I had bought a pirate-copy as aside from the dirt the whole picture was extremely poor.
In short these are good stories ruined by a cheap company that just wants your money.