Thank you for the prompt reply! I learned the following:
Downloading past purchases: was helpful to confirm the steps I had taken to download the already purchased (through the iPod) HD video to my computer. My computer did get it and store it in the Library.
iTunes: May be unable to transfer videos to iPhone, iPad, or iPod: This was the most helpful to confirm the capabilities of the iPod 2G, along with the techincal specifications pages I found on the Apple site.
I was still confused as to why I had gotten one HD loaded to the iPod and not another. Your reply affirmed that only the SD version actually gets downloaded to the (iPod <4G) even though the HD version (with included SD version) was purchased.
Here is where I went wrong: The iPod does not tell you the quality of the video. Only through iTunes can the HD-SD version be determined. iTunes was telling me I didn't have ANY video loaded on my device until much later in the process when I must have synched enough times to update that list. Once that got updated, I indeed had the SD version in the iPod. What threw me off track was that the SD version of that particular show is Widescreen Format which made me conclude that the HD version had been loaded to the iPod.
Closing out this saga, I got the HD-SD version in the iTune computer Library, allowing a transferable SD version for the iPod 2G following this document:
iTunes: Sync purchased HD videos to iPod or iOS device:
http://http://support.apple.com/kb/TS4223
Thanks for the help!