Calibre Web 2021
A recent update to Calibre Web version .6 added the series info, so there is no longer a need to add that to the templates. And they did make a few changes to the code for the publishing date.
Now to add the pub date so my python web scraping program can access it:
At around line 69 on /cps/templates/shelf.html
{% if (entry.pubdate|string)[:10] != '0101-01-01' %}
<p class="publishing-date">{{entry.pubdate|formatdate}} </p>
{% endif %}
—just after the {% endif %} for the series section.