I started by cutting the poplar to length. and selecting where the legs should go when looking at the front of the bench.
I then laid out construction triangles on all four legs to make sure that the dovetail cuts would not be made in the incorrect position.
I made a jig to make the dovetail flat and not take too long. I left the depth shallow and used a Stanley 190 to finesse the fit.
Final fitting was done with a chisel.
Here is the result with the assembled bench with the center section filled in solid.
Here is the bench with the center flipped over to the tray format.
This bench design is really usable with the clamping enabled from the center with the removal of the trays. I had a new end vise that I had purchased years ago but never used. I think that it will serve him well. He will have to buy and install the leg vise.
Thanks for looking.