As backers’ auditions go, “Gutenberg! The Musical!” — a wildly delusional conceit so full of itself that it boasts two exclamation points — doesn’t stand a chance of making it to Broadway. That is, unless it can convince an audience of potential producers that it is witnessing the greatest creation since, well, the printing press.

It greatly helps that this starry-eyed writer-composer duo from Nutley, New Jersey who are desperately selling their show — emphasis on desperately — are played by Josh Gad and Andrew Rannells, reunited 12 years after their terrific pairing in “The Book of Mormon.” It almost makes it all worthwhile — almost.

But meta-musicals have lost a bit of their winking novelty since this show began nearly 20 years ago, first as an extended 45-minute sketch for the Upright Citizens Brigade, then later for an Off Broadway run starting in 2006, followed by regional productions.

It took the reuniting of this premium comedic duo to give it the clout to get the show to Broadway (for real) for this limited run. Once again, the show is directed by that master stager of challenging properties, Alex Timbers, who helmed the original Off Broadway gig.

Scott Brown and Anthony King, who wrote the book and songs for the show (and were scripters for the wickedly clever “Beetlejuice” musical) fill their outlandish premise with loopy humor, insider jokes and simple silliness from the get-go — up to the sweet and surprising twist of the ending.

The stakes are high for Bud Davenport (Gad) and Doug Simon (Rannells), old buddies who have pooled their family inheritances to rent a Broadway theater (with parking). They’re backed…..|CONTINUED|