The Ipswich database tells us the house at 16 Summer St. was built between 1845 and 1856 

(From the Ipswich Vital Records: James Quimby, age. 29, a trader, was born in Sandwich, NH, and married Elizabeth S. Treadwell, age 26, daughter of William and Welcome Treadwell, Feb. 22, 1849.) Quimby, built the house at 16 Summer St., which was bought by James N. Webber. (Waters, Vol. 1). That house first appears in the 1856 Ipswich map. Quimby died in 185.

Locations of their graves are from the book Memento Mori:

• G — 151 — Elizabeth S. Treadwell) Quimby, wife of James Quimby, born March 14, 1822 ; Passed away Nov. 10, 1880. “She made all around her, happy.”
• G — 152 — My Husband, James Quimby, died Dec. 9, 1856, aged 38 yrs. 7 mos.

This photo from about the turn of the 20th Century is from the front of 16 Summer Street, looking  towards North Main St.

The house at 16 Summer Street is in the distance of this photo taken from the driveway between 17 and 19 Summer Street. Photo courtesy of the Ipswich Museum.

This is another photo taken from the same location as the above. Behind the young man is 16 Summer Street.

Maps