Guessing these are the original patio door and rollers in our 1983 home. The number 168 is stamped on the outside of the roller assembly. The roller wheel appears to be 1 1/8 in. in diameter.
Bob from SWISCO responded:
November 3, 2021
Check out the 81-090 to start. Compare the dimensions below to your roller and let me know if this matches what you need.