What I found was, "CutePDF Editor" a free online PDF editing tool. From their website you click, "Get Started" and you are on your way! I knew that I wanted to rotate the character sheet so I started there.
I clicked "Open File" and chose the character sheet PDF. The file loaded with no problem and I was able to then select the option to "Rotate Pages."
At first I couldn't figure out how to actually apply the requested change. Finally figured out that I needed to click the little check mark in the upper left of the screen.
Success! I saved the newly rotated PDF.
I closed the new rotated character sheet PDF file so I could begin the next step in my project.
With the character sheet turned upright I was ready to merge it with the other PDF files.
I chose "Merge PDFs" from the toolbar on the left.
I noticed that the CutePDF Editor allowed me to merge either PDF or image files. So, I decided to choose a cover image (s5fp.jpg) for my first page.
Next, I selected the Five by Five Fast Play PDF and the Super Five Fast Play PDF files, then finished up with the new portrait oriented Hero Sheet, and clicked OK.
CutePDF Editor merged my files for me and opened the result in the editor. I clicked "Save" and that was it. My newly combined PDF document for Super-Five Fast Play was done!
In retrospect it occurs to me that I could have merged my files first, and then rotated the character sheet on page 4 in the editor afterwards saving myself a few steps in the process.
CutePDF Editor is an amazingly useful online editing tool. And it saved me $70. Funny thing: after I completed the work that I wanted to do, I uninstalled the other PDF tool which resulted in my browser opening on a page that offered the tool to me for $45. If the tool had been priced at $45 to begin with, I probably would have went ahead and purchased it and never discovered CutePDF Editor.
As, it is ... I don't need that tool at all now, and I won't be buying it. Maybe they should have priced their product more reasonably to begin with. Anyway, I recommend CutePDF Editor. It's an awesome tool, especially if you work with PDF documents a lot like I do.