"Greens' Acres" is set 30 years before the series.
Several references are made to the fact that Bill loses a finger when he gets older.
One of Bill's customers tells Bill he's a DIY guy, which Bill himself becomes in "DIY Guys".
Near the end, Alice warns Bill to stay away from Nancy because she has a bad influence on him, hinting at the reason why they divorced.
Bill almost loses a finger when trying to free a rock from the hay baler which leads to Gramma warning him he could lose a finger one day; he actually does lose a finger to the hay baler as an adult years later as shown in "Cricket's Biscuits".