Did another dive into the newspaper archives and found earliest reference to Massimino as underboss from Anastasia in April 2002 after he got put on the casino exclusion list:
Joseph “Mousie” Massimino, identified by law enforcement investigators as the acting underboss of the Philadelphia-South Jersey mob, is no longer welcome in Atlantic City’s casinos.
Regarding the hierarchy of the family in general, this Anastasia article from December 2001, after Steven Mazzone's sentencing, said this:
Though authorities say it is too soon to outline a structured organization – underboss, consigliere, capos, etc. – they have identified several top Ligambi associates. They include his driver, Anthony Staino, a former official with the Atlantic City bartenders union and one of the targets of the gambling inquiry, according to a Philadelphia police report.
Two others who were identified as suspects in mob hits, Gaeton Lucibello and Michael Lancelotti, are also part of Ligambi’s inner circle, authorities say. Another key figure, they say, is Joseph “Mousie” Massimino, who is under indictment in New Jersey in a bookmaking-racketeering case.
I also found a Kitty Caparella article from April 2000 identifying Lancellotti as a capo, which is the earliest reference to him as such that I can find.
Regarding Angelina as acting underboss I also found this excerpt from an Oct 2008 Anastasia article:
Once described by a federal prosecutor as a "bully running with a gang of misfits," Angelina, 45, is believed by law enforcement investigators to hold a position of authority within the Ligambi organization.
Angelina was given a spot in the mob hierarchy, they say, when he returned to South Philadelphia in November 2005 after serving 66 months in federal prison on a racketeering charge. Mob leader Joseph "Skinny Joey" Merlino and five others were also jailed in that case. […]
Reputed mobster Louis "Bent Finger Lou" Monacello has been charged in two separate presentments in the case, one of which alleges he solicited another mob figure to assault Angelina.
Authorities allege that Monacello, who lives around the corner from Ligambi, first plotted with an associate to have Angelina killed. The associate, who was cooperating with the Pennsylvania State Police, reported the plot to authorities and wore a body wire to a second meeting. At that meeting, Monacello allegedly said that instead of killing Angelina, he wanted Angelina "beaten so badly he would have to be hospitalized," according to the grand-jury presentment.
Law enforcement sources familiar with the investigation said that Monacello was involved in a dispute with Angelina over the control and collection of gambling debts and that either Monacello or one of his customers had been threatened by Angelina.
Documents in the case indicate that Monacello had complained to Ligambi. But Monacello allegedly told the informant he would deny any involvement in the assault on Angelina if Ligambi questioned him about it.
In a taped conversation, Monacello said he would tell the mob boss, "if it was me, I would have just . . . killed him, OK?"
In the same conversation, Monacello used a epithet to describe Angelina and said he was the "most hated" member of the South Philadelphia crime family.
While not definitive, that would certainly look like Angelina was acting underboss from as far back as late 2005 to at least 2009 (when Massimino was released), his position being as a favour to Merlino would also explain the confusion around Staino as he became Ligambi's de facto no. 2 despite Angelina's title.
