Outlaws of Sonora (1938)

Dude's gang captures Stony and seeing the resemblance, Dude poses as Stony. Wanted for the robberies and murder committed by Dude, a wounded Stony escapes. After Doc Martin fixes him up, Dude's gang kidnaps Martin to operate on Dude. Now it's Stonys turn to pose as Dude as the Mesquiteers try to round up the gang.