It’s never too late to return to the fictional sharecropping community of Rainbow Valley, Missitucky, and sing about the fictional Irish village of Glocca Morra — at least if you’re a stunning songstress like Melissa Errico, who jumpstarted her career while still in her early 20s when she won the role of Eliza Doolittle in a short-lived 1993 Broadway revival of “My Fair Lady.”

Twelve years ago, Errico headlined a pocket-sized revival of the unconventional and politically-minded 1947 musical comedy “Finian’s Rainbow” at Off-Broadway’s Irish Repertory Theatre. (A full-scale Broadway revival of the musical flopped in 2009 in spite of rave reviews.)

Now 46 years old and looking as lovely as ever, Errico has returned to the newly refurbished Irish Repertory Theatre for a remounting of Charlotte Moore’s concert-style production, once again playing the ingenue role of Sharon McLonergan.

“Finian’s Rainbow” has a wild and complicated plot involving poor sharecroppers facing eviction, a quirky Irishman looking to strike it rich, his brash daughter, a leprechaun searching for his stolen gold and a racist white senator who is magically turned into a black man (conveyed here with a simple mask) and learns empathy.

Many of its targets for political satire (racial discrimination, immigration, a rigged economy, buying on credit) have become especially timely. One lyric even bemoans “the misbegotten G.O.P.”

Errico is joined by the ultra-animated Ken Jennings (the original Tobias in “Sweeney Todd”) as Finian and the dashing Ryan Silverman (“Side Show”) as her guitar-carrying beau Woody.

Even with just a four-member orchestra, the incomparable Burton Lane-E.Y. Harburg score (which contains romantic standards like “”How Are Things in Glocca Morra,” “Old Devil Moon” and “Look to the Rainbow” and many witty lyrics) still glows.