The first photograph is from the collection of Bill Bailey. He is standing in the center. Based on the handwritten note by Bailey the man standing on the left of the photograph is a Yugoslavian tanker, Standing to the right is Fred Keller. Kneeling left to right are an unidentified volunteer, Bill McCartney and [Paul?] Goldberg. Based on the uniforms, I believe this was taken in the early fall of 1937.
The second photograph is also from Bill Bailey’s collection. None of the volunteers are identified. The daughter of Gerry (Gerald) Doran believes that the volunteer in the prone position is her father. I cannot confirm this information though based on the information provided about Gerry Doran I do not believe that the volunteer is him. Doran was an early English volunteer who served in Co. 1 of the Marsaille Battalion. He was wounded in action, head and arm, and spent the remainder of his time in Spain in hospital. He was repatriated in June 1937.
The second photograph appears to date to the summer of 1938 based on similar photographs from the time period. Bill Bailey was serving as an Adjutant during this time period and the men may very well have been from his company.