In the 07 sire summary there is a list of about 50 bulls, mostly older pedigrees. Included are bulls such as Byland Gold Spear, Elbee Leader C087 (is that Gizmo?), JG Red Cloud, MF Pacer, and MFS Equity 43. Several of the Australian bulls have been homozygous polled.
When we bought bulls in western states, there was a single horned calf reported in SD by a bull we used here 100% polled calves (up to 50 or 60 daughters in the herd over time). So we did not turn in that bull as homozygous. We bought our first polled bull from Thieman's in 1970 and he was homozygous polled. Another later sire that never left us a horned calf was from Weston Shorthorns.
Wonder if the Irish & Maine influences have made the pure polled gene less common in Shorthorns in recent years?