In time I will get you somemore detailed drawings etc to you for the conversion.
Twas a long process because I wanted to have the dinette completely removable without modifying the original slideout.
Removing the sofa, leaving both end hinges in place, I cut a 3/8" plywood "false floor" [nominal 36" X 68"] that everything is anchored to (via “tee” nuts underside) and therefore no holes etc drilled or screws into the original slideout base which is over an inch thick but ~30" depth. I have the sofa and upholstered kick plate stored in case we ever sell the trailer and the new owner wants to return to the sofa config.
Since I left the sofa mechanism in place I then needed a method of securing the false floor into the slideout area, so i made the seat bottoms with a notch in them so they would then be placed inboard, then slid into the mechanism on both sides thus anchoring everything to that false floor.
If that is not the case for you, the much easier option is to remove sofa and mechanism and fashioning the two seats from 1” dimension lumber (or plywood etc) keep in mind that everything must fit thru the trailer narrow door, then mount them and the table base directly to the slideout base. Be advised that you have to figure a method of extending the jacknife sofa platform out to accommodate the 36" chairs.
Here are some measurements of the seats and table
Seat platform 22" by 15"height. Seatback 31" 36" is the minimum that RecPro makes. Thus the seat has ~ half inside the slideout, and half into the trailer. So not much floor space lost due to the extended seats.
Cushions are from RecPro, 4" thick 36" wide, seat pads 22", seat backs 12"
Since the slideout in the 2106ds is ~68" wide...for your plans of having the option of a sleeping area by removing the table and hardware...when all four cushions are layed flat, they just fit in the 68" slideout [the chair backs ensure that the cushions stay put]. Also, since the RecPro seats come with a generous supply of velcro to keep them in place....they can be positioned to ensure that everything stays put. I obtained the Mahogany seats direct from RecPro while they had a sale goin on. Their products are also available thru Amazon [slightly higher price, but expedited delivery].
As for a sleeping area, I have yet to address that. Remove the table and stanchions and a 24" X 36" platform would need to be inserted between the seats to spread all four cushions out for a relatively comfortable bed. That was another one of our dislikes of the sofa...you tended to be drawn into the cushion crack while sleeping. Not really comfortable!
RecPro:
https://www.recpro.com/recpro-charles-rv-dinette-booth-cushions-with-memory-foam/
The table, stanchions and bases are available thru Amazon or what have you. Table is 24" X 30", Stanchions are 25" length resulting in a table height of 26". One of our aggravations is that many eating locations have the table height uncomfortably high.
https://www.amazon.com/gp/product/B00HHRW2AK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
In our case, again I anchored the two base stanchions, cones and seats to the false floor plywood. The table top cone is screwed to an under-table plywood insert. Since the table has a recess, the table simply rests upon that insert even when underway. We have never had any problem with the pieces flying off. My philoshophy is that if indeed things do fly off....you have more serious problems outside the trailer or, you are off-roading [which is somewhat impossible in these lower-slung Micro-Minnies] at which point everything must be lashed down.
https://www.amazon.com/gp/product/B07KFWXTTJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I removed the original upholstered slideout kick-plate which had a lip above the slideout surface and could be a trip hazard when exiting the dinette area. So, peel and stick vinyle tiles were used as flooring and aluminum angle for protection of the new edge due to shoe scuffs and scratches of the false-floor plywood.
The result: A very comfortable seating area [at least for the two of us] with added table top space. The slideout operates with no problems, the added weight is minimal.
One thing that does need be stressed [from my understanding] is that any slideout need to be either fully in or fully extended. Sitting on any surface or adding any weight to a sofa or dinette with the slideout at mid-position is asking for trouble. At midpoint, the weight of the entire slideout is on those very small, but powerful electric motors and gears.
So, after saying all of the above, I am musing over a third iteration of the seat bottoms etc. Perhaps a lighter wood or material and also add that bed option should we ever have a guest.
To be continued.