The Cathedral of St. Paul’s refurbished gallery organ won’t be ready for Easter services on Sunday, as planned, due to “unforeseen events,” officials said Thursday.

The 50-year-old organ, the larger of the cathedral’s two pipe organs, is being reassembled in the choir loft after extensive restoration of the pipes and construction of hand-carved ornamental walnut cases to house them.

Workers are still finishing the project’s final phase, and it was decided to postpone the organ’s public debut until it is fully functioning, said the Rev. John Ubel, the cathedral’s rector. A new date has not been set. The final phase involves installing the pipes and fine tuning each one.

“While I understand the disappointment, believe me, it will all be well worth the wait,” Ubel said.

The cathedral launched a $3.4 million project in 2010 to restore both organs. The 86-year-old sanctuary organ was refurbished and reinstalled by Missouri-based Quimby Pipe Organs two years ago.

The larger organ’s 5,818 pipes then were shipped to Missouri for restoration, and University of Notre Dame architect Duncan Stroik was enlisted to design the organ’s new casework.

The organ’s console, which weighs more than 1,100 pounds, was delivered and installed in February.

About $650,000 remains to be raised for the project, officials said.