THE PIONEERS, WILL RODGERS JR, THE HANGMAN WAITS, also as Death Valley Days, S4E8

THE PIONEERS, WILL RODGERS JR, THE HANGMAN WAITS is also produced as "Death Valley Days S4E8 The Hangman Waits"
An old retired teamster Alex Grant played by Percy Helton is arrested for murder after he is identified by a shopkeep as the man that murdered his partner 15 years earlier. Only Grants memory and that of Harry Gander who is played by Hank Patterson ( Fred Ziffel in Green Acres) and his little black book will save the day.
Claire Weeks, James Seay, George Milan, Ken Christy, Clark Howat

An explanation of the same episode with different introductions
from Wikipedia:
During the latter years of the series, some new episodes were still being made while older episodes were already in syndication. In some markets, new episodes could even be running in competition with older ones. To make it easier for viewers to distinguish between old and new, some blocks of syndicated "Death Valley Days" episodes were shown under other series names and with different hosts. This was common practice at the time among syndicated series because it was easy to reshoot the hosting portions of an episode without affecting the main content. Alternate series titles and their respective hosts included Frontier Adventure (Dale Robertson), The Pioneers (Will Rogers, Jr.), Trails West (Ray Milland), Western Star Theater (Rory Calhoun), and Call of the West (John Payne). The last title was also often applied to the series' memorable, haunting theme music.