You might have trouble getting the codebase. I was employee #2 at a startup that shut down after about 1.5 years, and at the end we sold off everything.
I don't specifically know what happened to the source code but last I heard there were companies interested in it. Nobody that was going to do exactly what we were trying to do, but companies who could make use of a decent codebase if they could get it on the cheap. They would have gotten a few years of work for significantly less money (and time) than it'd cost them to build it themselves.
I wonder how many software developers take a dump of the source code repo on their way out of a company which has gone under? my guess is that most would, if only under the pretense of keeping some sort of historical backup in case noone else does... [admission: I did do that myself one time].
Do you know the process they went about in selling everything? I'm in a startup and we may be thinking of this too, perhaps approaching competitors. But still unsure about it.
For all the physical pieces of the company, I know he sent an email to the local tech-startup mailing list, at least. There's a pretty solid startup community here. For the digital assets, I really don't know, sorry. I assume it would be similar to seeking acquisition offers, but I'm definitely no expert.
I don't specifically know what happened to the source code but last I heard there were companies interested in it. Nobody that was going to do exactly what we were trying to do, but companies who could make use of a decent codebase if they could get it on the cheap. They would have gotten a few years of work for significantly less money (and time) than it'd cost them to build it themselves.