How to acknowledge oneself as the author of materials created in industry research position? I am an industry-based researcher. As part of my role, I develop various resources for use by our clients. They include manuals, codes, quizzes, factsheets and the like. In all cases, I am the sole author of these resources.

These resources carry the name and logo of my company. However, I also want them to carry my name (and title), so that I can claim authorship. I need to do this for a range of reasons, including demonstrating my research output, as well as ensuring no one else claims credit for them in the future. 

Implicitly, my colleagues know I am the author but as many of them are taking better job offers elsewhere or retiring, there may be no one left to 'vouch' for me. 

Currently, I put my contact details at the start or end of these documents, which basically says "For more information or clarification, contact [Name]". I want more that this but in a discreet manner i.e. I do not want to put my name on the cover page, as this would be too much in the "face of everyone".

The last point is important because these are industry resources and their "weight" comes from the fact that they have been developed under the auspices of my company. Hence, the copyright is held by the company. I have no issues here. Its the right thing, as I am an employee.

However, it is not the company but me who is developing these resources. My company will have no issue if I put my name somewhere in the documents but it has to be done discretely. The reason I am saying discreetly is because it is the company name and logo, rather than my name, that are important consideration for the end-users (including my CEO!).

I am looking for some strategies to have myself acknowledged in this context? In particular, I want it to be without any dispute that I am the author of these resources.
You should be able to place your authorship somewhere in the front-matter of the document without compromising branding.  I think the magic phrase you need is something along the lines of "Prepared by: [authors]".  

To take one of your examples: in a manual, after the cover there is often a set of front-matter with history and disclaimers and such.  You can add "Prepared by" as its own little subsection or insert it into the version and history information.  This makes it absolutely clear that you are the author, without putting yourself in front of the company's brand.