Ronald, could you make, or have made for you an “H” shaped frame constructed say from stainless steel tubing. The H section would be turned onto its side where the originally horizontal bar of the H would now be vertical. This now vertical part would be made from two tubes where one half of it would fit inside the other to provide a telescopic action. One side of what were originally the vertical sides of the H would now form the base, and would be attached to the fixed part of your cabin deck in the same place that your present wooden table supports are located, while the other side of the H would be attached to the under side of the table. The telescopic part forming the original horizontal of the H before it was turned onto its side would be drilled to take a stainless steel pin that would slide through in one position to lock the telescopic arrangement to support the table at its normal height for dining, and would be removed and reinserted at a separate point when the table was lowered for use as the bed base for sleeping. This would not interfere with your ability to lift the portable part of the deck so that you could check your bilge, instead it would simply take the place of your existing wooden table legs. It would also, I believe, be a lot less expensive than some proprietary fitting.
You might need to change the table top for one that exactly fitted into the space between your settee bases, and also fit a supporting batten along the edges of the settee bases in order to support the table edges.
Hope it works
Salty.