Got an answer:

We will always honor any warranty that came with the rod when it was purchased. Your rod came with a 15 year warranty, so if the rod breaks under normal fishing conditions (like on a hookset or casting), we would replace your rod with a brand new Imperial USA fly rod, and you would also get a voucher for $175 (to make up for the price difference). If the rod breaks accidentally (like in a car door), then we would replace it with an Imperial USA fly rod and you would also get an $90 voucher.

As far as spare parts, we will basically be using up any spare inventory in the near future. If we were unable to come up with the spare parts needed to repair your rod, we would fall back on one of the two above options.