Micheal does your trailer have its original 76 built frame? If so you should know installing a built in grey tank may with its
weight when full, be all it takes to push you into having to replace it.
A fast an easy alternative would be to get yourself a
small tote and carry waster water container. Just attach a garden hose to the grey water outlet on the outside of the trailer onto the tank which would be located outside the trailer. An even cheaper approach is to get a large bucket with a lid (such as
paint bucket) - cut a hole in the lid for the hose to fit in.
Edit to add: You may have a hard time finding anyone to share a photo of their grey tank on a 13'
Boler as they where not common to the 13' - more common to find on the larger Boler's.