u/Efficient-Book-2309

We opened a wall on the new screen porch edition to add wiring and insulation. Question is, do we replace the original planks or use modern sheathing?

The house was built in the 1930’s.

I opened up an exterior wall that is now part of a 3 season porch. There are these strange triangular hand formed lumps of concrete(?) above a window and level with the second story floor. Has anyone ever seen anything like this before?

Also, should I replace all the original planks or get modern exterior sheathing?