PRR #1223 was restored to operating condition in 1965 and operated on the Strasburg Railroad with sister 4-4-2 #7002 as late as 1989. Strasburg leased both engines from the Pennsy and restored them to operation. Both the #1223 and #7002 stayed in operation at Strasburg, with the museum taking over the lease from the PRR. In 1989, an ultra sound revealed the metal sides of the locomotives' fireboxe became too thin to allow for further operation without a significant investment and a long term renewal of the lease. There was also a concern regarding the "historic fabric" of the engine which could be lost in further restoration.