The best replacement for sketchup these days is OLD sketchup (version 8), from ten years ago. You can still get it. More on that at http://woodgears.ca/sketchup
Can you add it to your page? I found it via https://jayscustomcreations.com/sketchup/, which has a dropbox url that includes the magic string "FM-3-0-16845-EN.dmg". That's all I needed to make the Mac URL from your Windows URL.
