Possible Clues:

• Add to men relieving us in 31 days
• Fellows standing in for you and me in holiday month maybe make more
• Increase production of gunmetal endlessly
• Expand in summer with a fair amount of movement
• Summer resort finally supporting staff — that's swell
• Pad
• Expand
• Top up men for us during the course of a month
• A broken mug, and ten more to add to it