What are you seeking?
The saw in the photo already has a blade screw and washer. Amazon has several types of rip guides for circular saws. I just bought two for my worm drives.
Don't berate circular saws. Yes, there are not for fine woodworking BUT they are the first choice for break down large sheets of plywood by one person OR by a shop with limited table saw capacity. Just use a fine tooth blade when possible and cut with the good side down when possible to avoid splintering.
Place a small wood strip against the teeth and base when tightening the blade or removing it.
The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)