The death of a Pennsylvania woman in the coal mine she fought to work in is turning into a potential bonanza for her surviving husband and son.

Not only are there book and movie offers, but an unusual benefits battle has suddenly been settled in favor of the dead woman's family.

The death of 35-year-old Marilyn McCusker, who was killed near Osceola Mills in central Pennsylvania Oct. 2, gained national attention because she's believed to be the first woman to die in a deep-mine accident.

It was the same mine she had fought for nearly three years, charging she was denied work there as a miner because she was a woman. She won her case in 1977 and worked in the mines until her death.

Her husband, Alan L. McCusker, 28, an unemployed construction worker, also gained attention when it appeared he was ineligible to collect substantial survivor's benfits because Pennsylvania workmen's compensation law apparently prohibits payments to widowers.

But last Thursday, the day of a scheduled hearing for McCusker and United Mine Workers union attorneys to officially challenge the law on grounds of sex discrimination the mining company unexpectedly agreed to pay all due benefits.

The benefits are among the highest in the nation, according to the Pennsylvania Department of Labor. They could bring McCusker $227 a week for life unless he remarries. His wife's 16-year-old son by a previous marriage is to share in the money until he is 18 -- 23 if he attends college.

A lawyer familiar with the family and the case said, "She forced the mining company to treat her like a man, and now he's forced it to treat him like a woman."

In addition, McCusker says he has had to retain a lawyer and an agent to handle the influx of movie, television and book proposals to tell the story of his wife's life and death.

He said he has been contacted by "12 or 13 movie producers" and had been flown from his home near the small, stark town of Coalport to Hollywood and New York to be wined and dined by representatives of the entertainment world. One of those representatives, he said; has secured a job for his 21-year-old sister who was unemployed and living in Phoenix, Ariz.

And McCusker's lawyer, Richard Milgrub of Clearfield, Pa., who is a partner in a two-lawyer firm and a part-time public defender, says he has been contacted by Warner Brothers, David Susskind, Martin Pool Productions and others for movie rights to the story of Mrs. McCusker's life.

He said details are being negotiated for what he called a lucrative contract with a Los Angeles telvision producer for a two-hour prime-time movie, and talks are under-way with the William Morris Agency in New York for a ghost-written book by McCusker.

Through it all, McCusker seemingly remains unfazed. Last week he said he's almost sorry to have won the benefits argument without a legal fight. "I've won the battle, but lost the war," he said. "I feel I've let others down because now we can't change the law."

He noted that other women work in that mine, and there is no assurance that another fatal accident would yield survivor's benefits. "Maybe through the book and the movie we can get the law changed," McCusker said.

The law prevents payments to a widower "unless he is incapable of self-support at the time of his wife's death and be at such time dependent upon her for support." There is no comparable language pertaining to widows.

The McCuskers were married in 1975. At the time, Marilyn McCusker was fighting the Rushton Mining Co. of Philipsburg, which she had charged with sex discrimination after being refused a job as a miner.

Settlement of that suit in 1977 included retroactive pay and a sudden windfall of more than $30,000. That prompted McCusker to quit his construction job and set about building the family's "dream house," which he says is still unfinished.

His wife's story, he says, never was connected to the women's liberation movement. "In fact, if anything, she was an anti-libber," McCusker said. She and other women in the mostly mining area wanted the jobs because of the money. He said she was earning about $380 a week at her death.

Mrs. McCusker died of asphyxiation and shock when a portion of a mine wall collapsed. No one else was injured. Her husband is considering a negligence suit againt Rushton, saying a union investigation has uncovered alleged safety deficiencies at the mine; he awaits a federal agency's accident report.

For now, he says, "with all that's happened, it looks like i won't even need those benefits."