North starts answering questions. Washington opinion is divided as to what sort of impression the action-loving marine will make

While staying silent in his guarded Virginia home, seen only in brief glimpses between car and lawyer's office, Oliver North has become one of the most famous and enigmatic figures of the Reagan era. Without his will and love of action, the events that have become known as the Iran-contra affair might never have happened. Months of congressional testimony by the affair's other players have only intensified the image of North as the man who is sitting on all the secrets, Buddha-like, waiting his time.

Barring last-minute complications, that time is now. Today Colonel North is scheduled to appear for a closed-door interview with lawyers from the Iran-contra committees. Yesterday he turned over to congressional investigators seven binders containing his telephone logs, correspondence, personal calendars, and copies of the contents of 21 spiral notebooks.

Under a limited-immunity agreement reached between the committees and North's counsel, today's interview will be almost ritualistic, according to committee sources. The subject will be limited to how much President Reagan knew and when he knew it, and initial discussion will be informal. After this, North will be put under oath to answer questions.

He appears before the TV cameras for testimony July 7. Washington opinion is divided as to what sort of impression he will make. North's friends say his charisma will impress the public, as it has manifestly impressed many who know him. There is a sneaking suspicion among observers that North, medals ablaze, chest out, will cast a spell, making criticism of his actions seem petty.

Many committee members disagree. Sen. William Cohen (R) of Maine says North will be contrite: ``I doubt he's going to come in as a swashbuckling lieutenant colonel full of bravado.''

Cohen, along with several friends and former associates of North, paints a picture of a man corroded by the very events he set in motion.

Working with arms dealers, rich fund-raisers, questionable intermediaries, and other assorted private characters, North was immersed in a world that had a different moral code from the government and military. When one's partners are used to bribing for contracts, it probably becomes natural to believe that it is all right to keep cash in office safes or accept security equipment as a gratuity.

One friend of North's who has worked closely with him on projects says that he, along with the rest of the country, has been ``surprised'' by some revelations. This friend says that North may have good explanations for such things as the now-famous security fence, but that even if he doesn't, such relatively small wrongs must be weighed against his larger accomplishments. ``All it does is take a little luster off the star,'' this source says.

If the value of all the personal benefits North has allegedly gained is added up, it is minuscule compared with the amount of money that changed hands in the Iran-contra affair, this friend contends.

North still has strenuous public defenders. Last week a group of them, mostly associates from his days at the United States Naval Academy, traveled to Washington to stage a pro-Ollie rally at the Lincoln Memorial. But it has been a long time since President Reagan called him an ``American hero,'' and few in government, even those who could be sympathetic, are willing to give North an unlimited endorsement.

In a recent interview with reporters, the retiring head of the Marine Corps, Gen. Paul X. Kelley, was asked if he thought North was a hero or a bum. He said, ``The Oliver North I know went to the [National Security Council] in 1981. That Oliver North was an outstanding Marine Corps officer. I can't comment on the man that has been over there since '81. He belongs to somebody else.''

The congressional investigating committees hope to shed light on the NSC North. Among the things North may be asked about in public are:

The cover sheet of the so-called ``smoking gun'' memo, which laid out the skeleton of the Iran-contra affair. This sheet is missing, and if found or described could indicate President Reagan knew more than he has publicly admitted.

The security fence, and other items that indicate he may have benefited from Iran-contra money.

His relationship with the late central intelligence director, William Casey, who some feel may have been the affair's mastermind.