The men of “Diner,” from left, seated: Ari Brand, Noah Weisberg, Derek Klena, Matthew James Thomas, Aaron Finley and Ethan Slater. (Mobius New Media/Matt Urban)

— A moment of silence, please, for Older Boogie.

The character who served as narrator in last winter’s Signature Theatre world premiere of “Diner,” the musical, is no more. But do not grieve for long. His presence in the Barry Levinson-Sheryl Crow stage adaptation of Levinson’s 1982 film comedy was a real drag, a device that encumbered rather than cushioned the story of six young men in the Baltimore of 1959, none of them quite ready to grow up.

The cutting of Older Boogie — the more mature manifestation of the tale’s soft-hearted hard guy, Boogie (Derek Klena) — is some of the better news emerging from Wilmington’s Delaware Theatre Company, where Levinson, Crow and director-choreographer Kathleen Marshall have taken “Diner” for needed retooling. There are other positive developments: first and foremost, an Act 1 that flows more smoothly. This gives Crow’s fine period score, redolent of doo-wop and Sinatra and Frankie Avalon, more room to breathe. Some new casting proves advantageous, too, such as the addition of Noah Weisberg as trigger-tempered, insecure Shrevie; Ari Brand as sports-obsessed bridegroom-to-be Eddie; and Brynn O’Malley, the Dot of Signature’s 2014 revival of “Sunday in the Park with George,” as Barbara, the newswoman whose aspirations are stymied by pregnancy.

These are solid, incremental advances, and as much as I’d like to report that the creative team’s reworking is finished, some more is required. “Diner” the musical is still a bit flat, owing in part to the excessive burdens Levinson places on his own script. With his ambitious effort to widen the lens of the movie, to give equal time to the frustrated women in the men’s lives, “Diner” has fully nine arcs to establish and resolve. In such an intimate, character-driven musical comedy, that’s a lot of idiosyncratic detail to crowd in. At present, some of the characters and their relationships feel schematic — fainter echoes of the singular, and more robust, personalities of the film that launched the careers of, among others, Kevin Bacon, Daniel Stern, Mickey Rourke, Ellen Barkin and Paul Reiser.

How hard it has been for director Marshall to replicate that chemistry is evident in Wilmington. Many of the movie’s comic moments were improvised; it remains a tall order for the actors in the stage version — several of whom return from the Signature premiere — to have to plug into those distinct rhythms. Some scenes translate well, though — one of them concerning ladies’ man Boogie’s hilariously bad manners on a movie date, in a calamity framed wittily by Crow’s rocking song for the women, “Don’t Give it all Away.”

The underlying ambivalence in the marriage of Shrevie and his young bride, Beth (the excellent Erika Henningsen), is well developed, too, particularly through Crow’s plaintive ballad “It’s Good.” But the musical lacks the time and space to adequately flesh out all the subplots — even at a running time of two hours and 40 minutes. So episodes involving Barbara and Billy (Aaron C. Finley), for example, and tortured Fenwick (Matthew James Thomas) still don’t assert themselves satisfactorily. (Crow has made two song changes here; a new Act 1 finale for Fenwick, “I Got No Home,” replacing “Fenwick’s Song,” and an extra if wee bit obvious number for O’Malley’s Barbara in Act 2, “I Can Have it All.”)

Derek McLane’s original set and Paul Tazewell’s costumes, adapted here by James Kronzer and Amanda Seymour, respectively, successfully embody what “Diner” attempts to capture: a snapshot of a moment in time. The complete picture, though, is still waiting to come out of the darkroom.

Diner, book by Barry Levinson, music and lyrics by Sheryl Crow. Directed and choreographed by Kathleen Marshall. Sets, Derek McLane and James Kronzer; costumes, Paul Tazewell and Amanda Seymour; lighting, Peter Kaczorowski and Gina Scherr; sound, Leon Rothenberg; orchestrations, Mitchell Froom; music director, Seth Farber. With Ethan Slater, Tess Soltau, John E. Brady, Anne Horak, Jacqueline Beatrice Arnold, Rachel Stern. About 2 hours 40 minutes. Tickets, $35-50. Through Jan. 3 at Delaware Theatre Company, 200 Water St., Wilmington. Visit delawaretheatre.org or call 302-594-1100.