as a side note, from what i've seen, swallows tend to have a much shorter life-span than any other brooks, maybe it's the leather they use, but they stretch out really quickly, then you come to the end of the bolt, and they're done.
The swallow is longer than the swift, perhaps that why it have a shorter life span? (the stretching of the leather part).
The swallow is longer than the swift, perhaps that why it have a shorter life span? (the stretching of the leather part).