Citation with repeated information

Brian,

Yes, we can make it more concise—and add clarity, too.  To dissect the situation for our readers: you have two things to cite.

• The book itself, in Layer 1
• The website, in Layer 2

Layer 1: The imaged source

Most of your answers are in EE’s chapter 12 (Books).  At 12.75, you'll find the basic format for "Reprints and Revisions."

In your Layer 1, you have this:

Marriages, 1834–1855: gleaned from the Pittsburgh Christian Advocate (n.p. : Western Pennsylvania Conference of the United Methodist Church, 2000, reprint 2017), 

Our recommendation would be this:

Western Pennsylvania Conference of the United Methodist Church, Marriages, 1834–1855: Gleaned from the Pittsburgh Christian Advocate (2000; Reprint, N.P.: Archives & Ministry Team, WP Conference—UMC, 2017), 9, William Aspy to Hannah Hepler (m. 4 Jan. 1838), citing issue of 8 February 1838;

Explanations:

• When we cite a book, the author is cited first. If the publisher is the same as the author (EE 12.20 “Self-published Works”) then the publisher’s data can be shortened.  In the case of an individual author, the publisher’s ID could be shortened to “The Author.” In the case of a government agency that has been named as the author, the publisher could be identified as simply “The Agency.”  If the author is a church with a simple name, we could simply say “The Church.”
• In this case, the name of the author/publisher is a bit more complicated. The full identity includes a denominational organization, a specific conference of that organization, and an agency within that conference. The agency needs to be named also. It would be better to do it in the publisher’s field, with the rest of the ID shortened there, and to credit the "Western Pennsylvania Conference, United Methodist Church" as the author under whose name this source would be alphabetized in your source list or bibliography.
• In the title of the volume, the first word of a subtitle is always capitalized within English citations. (Basic citation rules at EE 2.60, “Capitalization, Publication Titles.”)
• For dates & the fact of reprint, virtually all citation guides, not just EE, use a standard sequence for citing these details. Inside the parentheses that contains publication data, we first cite the original date of publication. Then, after a semicolon,  the word “Reprint,” is followed by the current publication data. (EE 12.75)
• When we cite a book, we need to cite the specific page in the book. (EE 12.3, “Basic Format: Books …”)
• When we’re using a book of record abstracts, with many different items on the page, it is often useful (but not mandatory) for the citation to state the item of interest on that page. The item data should follow the page number, because we are saying “look on p. 9 for William Aspy to Hannah Hepler.” (See also the related comment under Layer 2, below.)
• If the record abstract identifies its source, we cite that source. Because that source is cited by the book, not the website, that data belongs in the layer in which you cite the book. Because that cited source applies only to that Aspy-Hepler marriage, it should specifically be attached to your reference to the Aspy-Hepler marriage.  Because the newspaper itself is named in the title of the book, you don’t need to repeat it in your source-of-the-source data.

Layer 2: The provider of the images

Your Layer 2 offers this:

PDF download, Western PA Conference, United Methodist Church (http://www.wpaumc.org/files/resource/historical_records/archives/marriages%201834-1855.pdf : accessed 28 July 2017); entry for William Aspy and Hannah Hepler, m. 4 Jan 1838; 

Our recommendation would be this:

PDF, Western PA Conference, United Methodist Church (http://www.wpaumc.org/files/resource/historical_records/archives/marriages%201834-1855.pdf : accessed 28 July 2017).

If you’ve had time to read our QuickLesson 19: “Layered Citations Work Like Layered Clothing,”you might recall No. 3 of our “three basic rules.”

“3. Details from one layer should not be inserted into a different layer.”

(The point has also been repeated in our just posted QuickLesson 25: “ARKS, PALS, Paths & Waypoints (Citing Online Image Providers),” which puts it this way:

“Never, ever, should details from one layer be mixed into the other layer.”

The website does not offer a database with an “entry for William Aspy and Hannah Hepler, m. 4 Jan 1838.”  The website offers the book that was cited in Layer 1.  That’s all the website offers, with regard to your item of interest. There is no database in which entries can be accessed through a query box. The pages are not imaged separately, so there’s no image number to cite. The website simply offers the book as one PDF document.

Layer 3: Citation to Source of the Source.

If the website did offer a database, then it would be appropriate to use a third layer to record what the website identifies as the source of all its data. That’s not the case here.

Assembled, your two layers would look like this:

Western Pennsylvania Conference of the United Methodist Church, Marriages, 1834–1855: Gleaned from the Pittsburgh Christian Advocate (2000; Reprint, N.P.: Archives & Ministry Team, WP Conference—UMC, 2017), 9, William Aspy to Hannah Hepler (m. 4 Jan. 1838), citing issue of 8 February 1838; PDF, Western PA Conference, United Methodist Church (http://www.wpaumc.org/files/resource/historical_records/archives/marriages%201834-1855.pdf : accessed 28 July 2017).

In the process, we've shortened 71 words to 57.

You also ask:

Is it valuable to include the publication location for discontinued newspapers, for example Pittsburgh (Pennsylvania) Christian Advocate?

If I were doing the research and the publication told me where to find the original issues, yes, I'd want to record that also. I'd be wanting to study those original issues for a lot more than just marriage records!