One of our customers in San Antonio recently picked up a 1953 Coleman 500 stove that appears to have seen very little use. He wanted to replace the small fuel-cap seal and return the pump to the original leather-cup style.
Nicole asked for a few more photos before recommending anything. Once she saw the other end of the pump, she could confirm that someone had replaced the original assembly with a later fixed-end version made for a neoprene pump cup.
The early pump assemblies used a leather cup with a square retaining nut.
She helped him find the proper leather-cup assembly, the S45 fuel-cap seals, and an original Coleman funnel with the smaller stem made for the small filler opening.
That small filler cap is original to the Model 500 and was also used on the 242 & 243 lanterns.