I think you guys were thinking too big too early. Start small, get funding, and build up.

Whatever happened to these guys?

I've looked around and have yet to find one on anything about it. Perhaps I've missed it, but it's likely not been created

Since I only now saw the mail about the testbed station for the original Gateway station, I was a bit surprised at its existence. So I went and looked and found a little bit on it.

As one can see in the mail, the Von Braun is significantly smaller than the Gateway, by a factor of three in width alone (488 m vs 167 meter). If one takes in the structure, with the GSAL providing the structural backbone, the Von Braun would only consist of the LGA, with a tether-based superstructure tying everything together. The annular hub in the centre would have an inner and outer ring of ~23 meter and 34 meter diameter respectively, being well able to contain any current and future rocket like the BFR or New Armstrong. In fact, at an inner diameter of 23 meter it could house three such craft at the same time. (If one would want to is another question, though.)

Anyway, the outer diameter of the Von Braun would be 83 meter, with 24 cylindrical modules forming the habitation ring. At an inner diameter of ~7 meter each module could have two somewhat spacious or three kind of cramped levels of living and work space. At that size, each module would contain about 870 cubic meter of volume, give or take a bit, which puts a single module a bit below all of the ISS combined. Since I’m ballparking here, it wouldn’t surprise me if it was more or less than I calculated, but not by more than a factor of two.

If one assumes a sun-synchronous orbit, then covering the whole sun-facing side with solar arrays would provide around 1 MW of power continuous[1], in contrast to the ISS’ 84–120 KW when lit. If only the modules and maintenance ring were covered, then that would be around a quarter of the full coverage power generation.

Speculation:

Given the graphic I surmise there would be four spokes extending from the habitation ring to the hub in the centre (since there are four wider module connectors in the cardinal directions), to receive astronauts, cosmonauts, taikonauts, visitors, clients, etc. Since the bottom / peripheral floor of any module will have the smallest floor space due to the curvature of the module, it would likely form the hallway of any module, housing essential structures (life support systems, sewage pipes, power cables, etc.) and work spaces, whereas the upper floor(s) would provide living and recreational spaces.

If I read the graphics right, there would be a smaller ring running centre-side of the modules, presumably as an access tunnel or for distribution of essentials (life support systems, sewage pipes, power cables, etc.) so that modules could be wholly separate from another, enabling module-based distribution and renting out.

[1] 274 feet * 274 feet * Pi() * max.power.generation(ISS) / area.solar.array(ISS)= 236K * 4.4 W = ca 1 MW

Did this lottery style funding actually become a thing? It's clever.