Although re-construction at the former U.S. Post Office by a private developer seemed to slow to a crawl over the winter months, the building is getting ready to be delivered to tenants.

Steve Grathwohl, asset manager with Westport Property Management, said the owners are working on punch list items and should be able to turn the main space over to the anchor tenant, Plan B Burger Bar, in the next few weeks.

"We should be done very soon," he said. Once that is done, he said, Plan B personnel will be able to come in to fit out the restaurant space.

Grathwohl said the owners are in negotiations with tenants for the four other retail spaces in the back of the building, but declined to name possible tenants.

Plan B, a chain with five restaurants in Connecticut and one in Massachusetts, is looking to open downtown by the late fall. It advertises burgers made with "100 percent verified humane" beef with no additives or chemicals, a selection of all natural, boutique bourbons and American craft beers.

"At this time we have not been given a turn over date by the landlords," said Plan B spokesman Rachel Hurvitz. "We can't wait to get in there."

She said there were "quite a few speed bumps" for the property's owner, 1262 Post Road Holdings, LLC, during the construction time that pushed out the time table "significantly."

The LLC purchased the post office from the federal government in 2012 for $4.3 million. Plan B had originally hoped to open in September of last year, but issues with getting a rock crusher on site, Grathwohl said, led to delays in construction.

Plan B's restaurant will occupy 4,600 square feet at the front of the building, which includes the preserved facade of the original 1936 Post Office.