Oxnard,
A study of the background of Charles Taze Russell, will reveal that Russell never claimed to be an Adventist. However, he does admit that it was his attendance at a Second Adventist (not to be confused with Seventh Day Adventists) meeting conducted by Jonas Wendall that he had his faith rekindled. Also, he fellowshipped with the Second Adventists from 1868 until 1878, when he quit the staff of an Adventist publication "The Herald of the Morning." He had a major disagreement with N.H. Barbour, one of his collaborators, who had rejected the teaching that Christ's death could be an atonement for sinners This is when he severs all ties with Barbour and Second Adventists. In July 1879 Russell began his own publication "Zion's Watch Tower and Herald of Christ's Presence."
So, I would say that Russell certainly was influenced by and worked with the Second Adventists, while never claiming to be one.