So, where do I find older marketplace content?
Normally you can choose the version in the dropdown menu beside the download button ->> but most assets are from > 4.3 
As the marketplace is still pretty “young” there is nearly no “old” stuff around. Or what exactly do you mean with “old”?
well just a few months back. I mean, I joined up with UE4 just a few weeks ago so I think that I’ve missed a few good contents. Maybe a full catalog might be awesome perhaps?
Some of the old stuff has been moved to under learn (like the Shooter example)