In reality, considering that CT Russell did not learn about Jesus' alleged return in 1874 until 1876, he missed the boat by two years, so could not be the 'slave' that was awaiting his master's return.
Additionally, since the first issue of WT was not published until 1879, it could be argued that NH Barbour was the "faithful slave", as he was aware of the 1874 date prior to Russell, and, in fact, was the one who convinced Russell of that date. Russell was 5 years too late by the time he began publishing the Watchtower. So much for being ready and watching...
Of course, Barbour learned this chronology from the Millerites/Adventists, so they too could be the "faithful slave"...
The Adventists, when 1874 failed as Jesus visible return, switched gears and said Jesus DID return in 1874....invisibly. They would not admit their mistake. In 1914, WT did the same thing...when Armageddon, or anything else, did not materialize as they falsely prophesied, they claimed everything they predicted DID come true...it just occurred invisibly.
It's all utter nonsense and a case of the blind leading the blind into a pit....