Question: The band Clock features P.J. Smith and a man that replaced what Def Leppard member?

Context paragraphs:
Slang World Tour: The Def Leppard Slang Tour was a worldwide concert tour by English hard rock band Def Leppard in support of their album Slang.  It was the first Def Leppard tour since the early 1980s where the band used an end stage rather than the centre stage.  The album itself was a radical departure from the band's signature sound.

Pete Willis: Peter Andrew "Pete" Willis (born 16 February 1960 in Sheffield, West Riding of Yorkshire, England) is a retired British musician, best known as an original member of the band Def Leppard.  He co-wrote many tracks and played guitar on the band's first three albums: "On Through the Night", "High 'n' Dry", and "Pyromania", which was being recorded at the time of his departure.  He was fired from Def Leppard in 1982 and replaced by Phil Collen.

Def Leppard (album): Def Leppard is the self-titled eleventh studio album by the British rock band of the same name, released on October 30, 2015.  It is Def Leppard's first studio album since "Songs from the Sparkle Lounge" (2008), marking the longest gap between two studio albums in their career, and their first one to be released on earMUSIC Records.  The album became Def Leppard's seventh top ten album after it debuted on the "Billboard" 200 at number 10.  The first single "Let's Go" was released 15 September 2015, alongside the artwork and track listing.

Long, Long Way to Go: "Long, Long Way to Go" is a 2003 song by British hard rock band Def Leppard from their "X" album.  The song was later included on the "Best of Def Leppard" compilation album in 2004.  It remains Def Leppard's last UK Top 40 hit single, reaching number 40 in April 2003.

Desert Song: "Desert Song" is a song by British hard rock band Def Leppard from their 1993 rarities and 'B-sides' album "Retro Active".  This song was an outtake from the songwriting sessions that produced 1987's "Hysteria".  Self-produced, it became one of the last songs to be released by Def Leppard bearing the songwriting and guitar-playing of Steve Clark, who died on 8 January 1991.  It was a hit on U.S. rock radio, reaching number twelve on the Mainstream Rock Tracks chart.  It was recorded as an instrumental for their album "Hysteria" (1987) but left off the album and was largely forgotten until the band decided to commit the song for "Retro Active".  On a day off during their 7 Day Weekend Tour, Elliott composed lyrics whilst listening to the track.  Elliott assembled the band and remains the only Def Leppard song to feature both Clark's guitar playing and Clark's successor Vivian Campbell on background vocals, although Campbell's contributions are uncredited in the "Retro Active" liner notes.

Def Leppard World Tour 2015: The Def Leppard World Tour was a tour by British rock band Def Leppard in support of their "self-titled album".  The tour started with 13 dates in Canada through April and May.  The end of May and beginning of June was spent playing 12 dates in Europe before Def Leppard returned to the United States for 48 dates with Styx and Tesla from June to October.

Clock (band): Clock is a band featuring Def Leppard guitarist Vivian Campbell and P.J. Smith, who sang backing vocals on Def Leppard's cover of the Sweet song "Action" on Def Leppard's "Retro Active" (1993) album.

Joe Elliott: Joseph Thomas Elliott Jr. (born 1 August 1959) is an English singer-songwriter and musician, best known as the lead singer of the English rock band Def Leppard.  He has also been the lead singer of the David Bowie tribute band the Cybernauts and the Mott the Hoople cover band Down 'n' Outz.  He is one of the two original members of Def Leppard and one of the three to perform on every Def Leppard album.

Downstage Thrust Tour: The Downstage Thrust Tour was a North American concert tour by English hard rock band Def Leppard.  It began in Cincinnati on 27 June 2007 and closed in Saskatoon, Saskatchewan on 2 October 2007.  Def Leppard played 52 shows in 52 different locations throughout the course of the tour.  Members of the Def Leppard Fan Club had the opportunity to purchase tickets for shows via online ticket presales a few days before tickets went on sale to the general public.  The tour was produced by Live Nation.

Vivian Campbell: Vivian Patrick Campbell (born 25 August 1962) is a Northern Irish rock guitarist.  He came to prominence in the early 1980s as a member of Dio, and has been a member of Def Leppard since 1992 (replacing Steve Clark).  Campbell has also worked with Thin Lizzy, Whitesnake, Sweet Savage, Trinity, Riverdogs, and Shadow King.

Supporting paragraphs: Clock (band) Vivian Campbell
Answer: Steve Clark