Directory within a Directory within a Directory

I’m a little perplexed with this directory that I have come across. Essentially it’s a volume that encompasses several areas, each with their own directory. One of the areas is London. The persons I am looking for are found in the commercial directory section of the London directory. Ancestry has split up the directory into 2 sets of images (London only) https://www.ancestry.com/imageviewer/collections/2583/images/m0135-00001?pId=6665775 See image 2 & 3 for cover pages.

I have attempted a citation based on another post in this forum but given the complexity of the directory and how Ancestry presents it, I'm not confident I have it right.

Layer 1
The June Edition of the Post Office London Directory, 1845.:Comprising, amongst Other Information, Official Directory; Commercial Directory; Court Directory; Parliamentary Directory; Postal Directory; Banking Directory; &c. &c. &c., (London: W. Kelly & Co.,), 321, col. 1, entries for James Knowles, watchmaker and Joseph Knowles, watch and clockmaker;

Layer 2
imaged as "UK, Midlands and Various UK Trade Directories, 1770-1941," Ancestry (https://www.ancestry.com : accessed 17 July 2020) > Miscellaneous > 1845 Post Office Directory of London and Birmingham with Warwickshire - Part 2 > image 325;

Layer 3
Source of original: Dudley Archives & Historical Service. Accession Number: R 375/LD 913.42. The London Directory was published as part of the Post Office Directory of London and Birmingham with Warwickshire and Part of South Staffordshire directory.

Questions:
Do I need to mention that the persons were found in the ‘commercial directory’ and if so where?

Ancestry cites “UK, Midlands and Various UK Trade Directories, 1770-1941 [database on-line].
Original data: Midlands Historical Data collection of Trade Directories. Tony Abrahams. Midlands Trade Directories 1770–1941. Midlands Historical Data, Solihull, West Midlands.” However, that information differs from the very first page where it states the source of the original. I chose to use what was on the first page, because I could verify that the Dudley Archives has the directory in its possession. Should I use the word ‘citing’ before I go into layer 3?

I didn't attempt to shorten the title since quite frankly I don't know if I should and if so what to take out...any thoughts on that?

Thanks.