I am open to removing it all together. Could I just pull the window and and frame it in with dimension lumber? Maybe all treated 2x8? Since the block is 8" this is the biggest I could fit at least as framing, them header could be bigger if needed.
The deck was installed when the house was built.
I think I may see where some of the load it going. The deck joists and the floor joists are nailed together. The floor joists are sitting on the sill and the deck joists are also sitting on the steel angle (about 3.75" x 3.5") above the window that holds the brick.
Could this be why the sill has not deflected too much?