I suspect that one of the underlying causes of thr problem here is that "Germany" is something that doesn't exist as a formal political entity until 1871, so even though there was a common economic German union of sorts (the Zollverein) and some overarching cultural and political institutions, the German states were a pretty diverse lot in the 1830s and 40s (Marx's German period). The economic and social structure of Prussian Silesia could be quite different than Prussian Rhineland. Thus a lot of the high quality historical surveys tend to be regional studies. An exception to this is David Blackbourn's The Long Nineteenth Century which covers a broad amount of German history. One of the regional studies to look at is Jonathan Sperber's Rhineland Radicals which examines the economic and social undercurrents that exploded in the Revolution of 1848, which brought Marx a degree of public notice. Brendan Simms's The German Revolution of 1848-49 also covers the 48ers, but more broadly than Sperber.