I thought I'd let you see how the patch looked after the hydraulic cement cured. The cement is a darker gray than regular concrete.
Here's is a before photo. And here is the after photo.We are back to working on the duct work in the crawl space. What a mess. R barely has enough room to crawl. I was able to hand him small items through the register in the floor but that will stop once we attach the long runs of duct work.
Check out this photo of the crawl space. Not much crawling space plus it's decorated with nice cob webs and left over old disconnected knob and tube wire.