rebuild

In selecting a contractor how important is that they do the project in a certain amount of time? How long do you see a typical chain or belt project take from the purchasing of the land to when the first car runs through it? What can a contractor do to differentiate itself from other folks...

I think this is leaking lexair valve but wanted to see if you all agreed. PDQ G5 pump station. If so where to buy rebuild kit? And any advice (or videos) when rebuilding. I’m attaching photos and video for reference