The actors I found that were in LITB and Rifleman are adding up.

Edgar Buchanan
Harlan Warde
Sue Randall
Johnny Collier who played David Manning
Rusty Stevens
Norman Leavitt
Billy Hughes
Stephen Wootten who was Clyde Applebee
Ross Elliot
and of course Cheryl Holdridge.

Diane Brewster had a prominent appearance on TR.

William Schallert
John Hoyt

What, no Candy Moore? Amzie Strickland? Jean Van der Pyl?

Nope but I thought of someone else; Karl Swenson who played Eddie’s father and was in The Vision.