Luke Perry's character in Quentin Tarantino's "Once Upon a Time in Hollywood" is Wayne Maunder playing Scott Lancer from the tv show "Lancer."
Lancer was very different from all other western shows of the day, as it was intended to be deadly serious. Among other things, the pilot depicted a dead rancher hanging from his feet and implied the rape and murder of the rancher's wife. Also, while there were obvious nods to the modern audience (such as Scott wearing a modern knit shirt) the series avoided such cartoon touches as patent leather vests and costumey western wear such are were seen in The Big Valley (1965).
Premiered on the same date and at the same time as the premiere of The Mod Squad (1968)---Tuesday, September 24, 1968, at 7:30 p.m.
While Lancer clearly exists in a different reality than The Big Valley (1965), they are both set in California's San Joaquin Valley. They virtually occupy the same exact land.
All the main characters were born in December.