This gazebo is very similar to no. 2. On this, I haven’t made any separate inner floor. The corner posts goes through the base and are glued on the underside. I don’t know if you think this is trickier than the others but I wanted to try this.
I have added some pictures as it is a slightly different design. Use the assembly instructions on Gazebo no.2 for the rest.
You can find the file here.
Glue the bottom frame on the base.
Insert the corner posts through the holes in the base.
Glue the tabs down on the bottom frame.