"I had to listen to my mother," he says with a shrug. Then he turns back to the coat, and slides the needle into the sleeve.
Now 75, the white-haired DiMucci is like a tenured professor on a shrinking faculty: a small-town tailor in the age of big-box stores and online retailers.
And soon DiMucci will have to offer his expertise elsewhere. Within a few weeks or months, Frank DeRito Fine Men's Clothier, where he has plied his craft for 14 years, will close.
In June, the shop's founder and owner, Frank D. DeRito, died of a heart attack. DeRito's family has opted to shut the business down. For three decades, it served local jewelers, lawyers, and Wall Street traders alike.
DiMucci had become a draw in recent years, admired for his talent and personal touch.
"He's one of the few people I've met," says dentist Russ Bechtloff, from nearby Holland, "who knows how to make my body look flattering."
It took DiMucci decades to refine his skill.
After being encouraged by his mother to start stitching at age 10, DiMucci moved to America at 18.
Eventually he landed a job at the Botany 500 plant at 23d and Walnut Streets in Philadelphia, where he helped manufacture up to 6,000 suits a week.
DiMucci married and had two daughters. First they lived in South Philadelphia, then moved to the Northeast. For the next few decades, DiMucci kept stitching at various Philadelphia locations, utilizing the same hand position he learned as a boy.
Talk to DiMucci for a few minutes, and quickly discover that he's not all that interested in his own history.
Invariably, he'll instead end up showing a garment. The clothes, the fabric, the incisions, the cuts - that's what he wants to talk about. This is how a lazy tailor screws up a sleeve, he'll say. Or here, look at the bottom of these pants - they look so much better hand-stitched.
DeRito's family attorney, A.J. Sciolla Jr., says DiMucci's passion has kept him young. And DiMucci, he says, possesses a skill level that few tailors do anymore.
"The craft has gone by the wayside," Sciolla says. "It's rare you find the individuals who have the talent to do the handwork."
Lucieno Blancato, a friend of DiMucci's and a Newtown landlord, concludes there just isn't much demand anymore.
"If you don't work in a bank," he says, "who wears a suit?"
DiMucci isn't sure what he'll do when DeRito's shuts for good. But he wants to keep working. He's never really done anything else, he says, and retirement is out of the question.
"If I retire," he says, "I'll either die or go into a nursing home."
Standing over the gray sport coat, DiMucci licks his fingers and readies a cuff to be stitched. He offers a final thought on the matter.
"When I work," he says, "it makes me happy."
Again, he pricks the needle into the wool.