“I have definitely made and lost friends,” said Mr. Chahalis, 47, presiding over a neighborly Monday night crowd at the old P & G bar at the corner of Amsterdam Avenue and 73rd Street.

Mr. Chahalis’ great-uncle Peter and grandfather George first lit up the ancient Upper West Side watering hole’s iconic neon “Cafe Bar” sign back in 1942. (“My great-grandfather Peter gave them the money to open the store,” he said.) Come 2009, the husky, fourth-generation suds-slinging scion will have to pull the plug.

Despite a petition drive that netted nearly 4,500 signatures in support of the old bar staying put, the landlord has refused to renew his lease, which expires on Dec. 31, in an ongoing attempt to land a more upscale, higher-paying tenant.

Mr. Chahalis now plans to reopen the 66-year-old neighborhood institution just a few blocks away, after signing a new 20-year lease on the former Evelyn lounge space at 380 Columbus Avenue; same familial name, same friendly service.

The question is, will anyone recognize it?

“They put a couple of dart boards in there and a couple of pinball machines, maybe even I would go,” said retail broker Stu Morden of Newmark Knight Frank, who has the dubious distinction of being the listing agent for both the bar’s existing and future locations. (Mr. Chahalis noted, though, that he arrived at the new space without the broker’s help.)

Mr. Morden has yet to officially sign a new tenant to replace the old bar, long rumored to become a bank branch, albeit certainly not now, what with the current financial crisis and all. “We have a deal in the works,” the broker said, without getting into specifics.

Adjacent spaces, formerly occupied by a deli and a pizzeria, have been leased to fancy chocolatier Jacques Torres and the high-end Italian eatery and specialty foods shop Salumeria Rosi. “We think that this particular store will add yet another nice dimension to that corner,” Mr. Morden said.

MR. CHAHALIS, meanwhile, is cautiously optimistic about carrying on the family business on an entirely different corner, comforted by the fact that at least his old bar is expanding.

“I’m very psyched,” Mr. Chahalis said of the new location, a sprawling, 4,300-square-foot subterranean space, which measures more than four times the size of the original, “But,” he added, “I’m going to be on edge until everything works out.”

Brushing aside empty bottles and setting his laptop computer atop the bar, Mr. Chahalis pulled up a blueprint of the new space and proudly outlined his vision for a more modern, somewhat less gritty P & G, with a stage for live music and even a full kitchen, which the existing so-called “bar and grill” actually lacks. Patrons currently quell their hunger pangs with tiny bags of Cheez-Its and Doritos hanging above the cash register.

“We’re going to do steak and chops—like the sign has said forever,” Mr. Chahalis said with a smirk. “We’re also going to do burgers. I make these awesome teriyaki garlic-saffron-rubbed burgers. We’re going to do chicken wings and legs. I make my own hot sauces. I make a buffalo sauce and a hot teriyaki. …”

The new venue will also have a more refined look than the previous stripped-down dive. One corner of the new L-shaped space, for instance, will feature a fireplace, chess tables and shelves of books. “I want to really do it up like a man’s study in deep burgundy and walnut,” Mr. Chahalis said, explaining, “On Columbus Avenue, you can’t just open a shithole.”

He steadfastly refused to comment for this article, however, on the fate of the bar’s famous signage.

The future of the blazing red, yellow and green Art Deco-style script, often seen in the backgrounds of films and television, including Donnie Brasco and Seinfeld, has been in doubt for quite some time.

In 2006, Mr. Chahalis was shocked to find out that the building’s co-op board had submitted plans for a new storefront renovation plan that called for replacing the well-known sign. He pleaded with local leaders to intervene.

Robert Tierney, chairman of the city’s Landmarks Preservation Commission, publicly stated his “concern about the iconic sign.” The building’s architect, David Acheson, ultimately promised, “The P & G sign would remain as long as that tenant remains,” and the landmarks panel passed a stipulation that “replacement of the sign shall be approved by the commission.”

At the time, Mr. Chahalis hoped to hang on to both the location and its bright beacon. “Our ideal would be to work out a new lease,” he told The Observer back then. “If we can’t do that, our next step is, where can we relocate? And can we bring our sign with us?”

Now that his intended renewal has been nixed and his plan-B relocation is all set, the signage issue becomes the next hurdle. And a tricky one at that.

Beyond the mere logistics of physically removing and reinstalling the neon lights, the process would likely require not one but two public approvals, as both buildings fall under the landmarks law.

And who knows what the bar’s new neighbors, including the esteemed American Museum of Natural History across the street, will think of the strip’s substantially increased wattage.

ALL THE POLITICKING and wrangling with various landlords so far has caused Mr. Chahalis’ family much grief already. The struggle has been particularly taxing on Mr. Chahalis’ father, P & G owner and family patriarch, Tom Chahalis, now 73. “He’s been nervous as hell, very, very stressed out,” the younger barkeep said. “It’s a tough business. … I know I don’t want to be doing this when I’m 73.”

The elder operator can find solace in the fact that the family legacy will survive, at least in some fashion.

“When he saw the new space, the first thing, he’s like, ‘Oh my God, there’s so much room, it’s going to cost so much money to fix up.’ And I’m like, ‘Dad, look, there’s sconces in all the walls, we checked all the electricals, there are four central-air heating units. …’ After that, he said, ‘This is really nice.’”

cshott@observer.com