The Over-the-Hill Gang (1969)

A retired Texas Ranger and his three aging pals are hired to clean up a lawless town.

Director:

 Jean Yarbrough

Writers:

 Jameson Brewer, Leonard Goldberg (story)

Stars:

 Walter Brennan, Edgar Buchanan, Andy Devine - via IMDB 

https://archive.org/details/TheOvertheHillGang