Building Joomla's Fields Component when it does not exist in your System
I do not know why this came up, but the Custom Fields component which was introduced to Joomla in version 3.7 did not exist on my system and it would not install on Joomla Updates.
Quite a bit of configuration patience went into getting it installed. One of the issues really was the "NA" statement from the Joomla "Discover Panel". It indicated that there was nothing to install, and Update indicated the same.
The trick was to extract the Full current Package Install into a separate folder (in my case a separate drive all together) then to move and merge the contents of the Components/com_fields folder.
However additional configuration was required, again using the Discover and Install aspect of Joomla's Manage Menu Set. Not only did the component need to be installed but the System component (plugin I believe actually) had to be enabled, and the different Field elements also had to be installed and subsequently enabled.
Finally, Cache needed to be cleared and everything showed up. Viola. Happy me, though, I am not really sure I want to use that aspect of the system. Knowing me though, I probably do. I will post more here or nearby if there is anything of note.
Oh, and by the way, don't just extract the Joomla Package onto your working system. I did that and lost system control. I did do a full backup just before this so I was able to pull an immediately preceeding restore. However, it was from that file set that I was able to pull the component/com_fields folder. Worked like a charm. I need to unmount that drive next. Easy enough.