Complex sentence: Impressed by Gifford's combat record Waco offers him a membership in his private circle as a radio operator that ends when Gifford beats up Homeier when he makes remarks about his wife's photograph.
Split into simpler sentences: Impressed by Gifford's combat record, Waco offers him a membership in his private circle as a radio operator. This ends when Gifford beats up Homeier for making remarks about his wife's photograph.