Orval D. Seydlitz, who was born in a dirt-floor farmhouse in Nebraska and became an accounting firm partner in Toledo after studying on a piece of plywood plunked across two orange crates, died Friday in St. Luke's Hospital. Mr. Seydlitz, a month shy of his 82nd birthday, continued to do accounting work for his clients even though he had been hospitalized for nearly six weeks. The cause of death apparently was a massive heart attack, his daughter Jo Ann Bujarski said. An accountant with Ernst & Ernst beginning in the 1950s, and then with the firm after it became Ernst & Young, Mr. Seydlitz advanced to become a partner in 1970. He was expected to work weekends during the busy tax season, and he honed his tax preparation skills by working on returns on Sundays.