City Center’s annual Encores! Off-Center series (which brings rarely-seen off-Broadway musicals back into the spotlight) comes to a finish this week with a lively staging of “Kurt Vonnegut’s God Bless You, Mr. Rosewater,” a long-forgotten adaptation of Vonnegut’s 1965 novel about an inebriated millionaire/volunteer fireman who plots to give away his family fortune to the misfit inhabitants of a poor Indiana community.

The musical, which received a short off-Broadway run in 1979 and has been little heard of since (probably because it did not receive an official cast album), marked the debut of composer Alan Menken and lyricist-bookwriter Howard Ashman, who would go on to write “Little Shop of Horrors” and the scores for the Disney movies “The Little Mermaid” and “Beauty and the Beast” before Ashman’s untimely death from AIDS in 1991.

Directed by Michael Mayer (“Spring Awakening”), the cast includes such Broadway regulars as Santino Fontana (who just played John Adams in the Encores! “1776”), Skylar Austin (who appeared in “Spring Awakening” before achieving fame in “Pitch Perfect”), Brynn O’Malley (“Honeymoon in Vegas”), Rebecca Naomi Jones (“Passing Strange”) and Jeff Blumenkrantz (“Bright Star”) — plus a cameo from James Earl Jones, who arrives at the end as a sort of deux ex machina.

A freewheeling musical comedy with political themes and a serious streak underneath it all (not unlike “Urinetown” or “The Book of Mormon”) “Mr. Rosewater” faithfully reflects both the novel’s haywire plot and socially critical tone. The songs are fresh, fun and occasionally heartfelt, especially when Eliot Rosewater (Fontana) opens up about the traumatic past that led to his recreation as an overly generous philanthropist. The storytelling can be rough and chaotic, but that is to be expected with this kind of property.

I would not be surprised if this production serves as the steppingstone for a longer run. However, even if that does not happen, it should — nay, must — receive a cast album, which will encourage amateur and regional groups to produce it. Otherwise, “Mr. Rosewater” could very well fall into obscurity for another three decades.