Steve, it could be done. I'm sure that the gutter material can be purchased and cut to length. You will also have the get the OEM gutter end caps (drains). I never figured out why our BH has what you discribed....but only over one slide.....go figure. Get some gutter extensions and install them. Wal-Mart has them, about $4.00 for a pack of 4. Helps keep the black streak's off the side of the trailer. Note: after you install them...use claulking to seal them to the gutter, top and bottom.