Here's a neat clip of The Jordanaires doing "Working On The Building" years before recording it witl Elvis. In that 1960 cut, there was the addition of Milllie Kirkham.
This footage must date from the period 1954 - 1958, when the group was formed by Gordon Stoker, Hoyt Hawkins, Neal Matthews Jr., and Hugh Jarrett. By 1960, Jarrett had left the group and had been replaced by Ray Walker.
https://www.youtube.com/watch?v=LXYAEqrRESE