Local historian Richard Duffy reveals the common thread behind some of Arlington's most beloved historic buildings. Roger shows Kevin how he's using new granite steps with an antique look to dramatically improve the appearance of the front entry. To help with the tight fit against the house, Roger places the middle step on a bed of ice, so it will melt right into place. Inside, plaster contractor Bob Bucco repairs the severely damaged plaster mouldings and medallion by hand, while 3D printing specialist David Kempskie arrives to show how the repairs can also be made in a computer, thanks to state-of-the-art 3D scanning, modeling, and printing technology. Back out front, it's time to finally add a railing to the entry porch. Norm and Tom review the design options provided by the architect, then get to work fabricating the balustrade, which features a whimsical and period-appropriate flat-stock baluster that is custom-made on site.