You can steam clean it to remove any green algi, mold, mildew. Brick must breath, and I don't think there is any type of preservative that is recommended for brick.
If the morter is crumbling, the only thing that can be done is re-pointing. After 60 years, morter joints start to weaken.
However, I can only guess what your best option is without looking at it myself. I recommend getting one or more professionals to look at your house and see what they think.
Sincerely, Bob V.
© 2017 Renovate Your World LLC