The pool, the auditorium and maybe the pavilion were once the
conservatory buildings. Looks like the old buildings were gutted out
and the frames were kept and then remodeled.
All three current buildings are lined up as shown on the old photos of
the original buildings. Definitely the pool building is original.
The windows and the wall look the same from the old postcards.
 

This is the side of the swimming pool entrance area.
This is the current swimming pool building but the park office was added later.
The office today is built on this side where you see the four murals behind the mound of dirt.
(Anyone remember the murals?)
 

Here is a view of the pool entrance area.
The same counter is still being used today.
 

Notice there was no gym at this time,
that's because the gym was part of the auditorium as you see in the next picture. 
 

Today this the auditorium without the basketball court.
The dark shade of the picture is the stage.
Lower left is the entrance to the kitchen.
 

This is the opposite side of the auditorium.
The gym is being built on the other side of the wall with the scaffolding.
Note the floors with the court markings.
 

The roof is being redone above the auditorium.