Here's the promised update. I didn't have my Apple ID/Store access set up. I found a link to DL El Capitan as stated above. I opened the .dmg file which had ended up in my DL folder. That opened a .pkg file as described above. I was concerned that when I opened the .pkg file, it had an install process which wouldn't allow me to install to the empty SSD, but would allow installation to the Mac HD. I didn't want to upgrade the Mac HD to El Capitan at that time because of concern over breaking things. I finally realized the .pkg file was an installer for the El Capitan installer. I installed to my Mac, the installer was installed to my Applications folder, and when opened looked just like what krs had posted. I opened the installer, and it allowed direct installation to the new, empty but formatted SSD in the external enclosure. I went out for the evening, leaving the Mac to do it's thing. When I got home, I was greeted by a new screen, with a set-up menu. I shut my computer off using the power button. I swapped drives, but didn't connect the old, now external drive. I booted the computer, went through the set up and now I have a fast, clean and more up to date MBP. Once set up, and after playing with the apps, etc. I connected the old now external USB drive, which loaded very quickly. I am playing with old apps and files, and seeing how things work. So far all works very well.
Thank you all for your time and effort helping me sort this out. Thanks especially for the extra mile walked by krs, who's screen shot of the installer made me realize what was actually happening.
I'm happy that I joined this great community.
Have a great day!
