I'm not surprised that the photographs have such professional quality.
Many agencies such as Bridge and Tunnels had the opportunity in the Great Depression to hire top notch, down-on-their-luck professionals in many disciplines. And many of them remained in public employment afterwards as they'd found secure jobs with favorable pensions etc. were worth keeping.
But I'm a bit upset that you posted this because now I may have to figure a way to sneak out of work some afternoon this coming week for a quick visit!