No start after changing glow plugs and filters. (What did I knock off)

[Judge]

Ater changing the glow plugs and filters on a car that had sat for nine months the 1976 300D won't start. Likely I knocked a vacume or linkage off. What is likely?

Other observations. All the filters were very dirty. The loop glow plugs were intact, but harder than it seemed right to pull out after being unscrewed.

The clear small fuel filter has a air bubble in it after I installed it. That looks wrong.

As far as I can tell I reinstalled all the vacume lines, but I've only got the basic knowledge.

Thanks