After 157 years — that’s 628 changes of season — the Bangor Theological Seminary’s Maine Hall is getting a facelift this summer that combines the best of old and new.

Funded by the seminary and the state Historic Preservation Commission, the Bangor Slate Co. has spent the summer patching the brick building’s worn mortar to keep water out like new mortar, while matching the color and texture of the 157-year-old mortar.

Bangor Slate also repaired, caulked and painted the building’s 130 windows, painted the building’s trim, and built a new copper gutter system.

A notable addition to the building was put in place on Tuesday when workers installed a decorative wooden shutter at the peak of the five-story structure. The louvered, fan shutter replaces a similar one which shows up on old photographs of the building, but which has been missing for more than 20 years.

The new shutter, milled by Owen Gray and Son of Brewer, covers brickwork that seminary officials say may be as old as the building itself, although it does not match the rest of the building’s facade.

Bangor Slate proprietor Walter Musson said that he expects to finish the restoration project by the end of September.