This might help someone else dealing with a holding tank issue or someone wanting to take out the old one or put in a new one in an Endeavour 37.
The mod shows how I cut the V-berth platform for easier access to the holding tank area and ....
...how there is now room for a 20 gallon tank.
More pictures and info here....
Endeavour Plumbing page 1
Links to Our Endeavour, Our MacGregor & Our Trips