The hobo knife is just a cheapo. I don't think there's anything special about it. Your talking about the camp knife with fork and spoon right?
A little word of advice on buying old knives- Never assume that "cheap" or "junky" means worthless. Some cheap, junky knives can be worth hundreds of dollars, or more.
Conventional thinking is that knife collectors only want expensive, high-quality knives. But knife collectors can be an
eccentric bunch. Sometimes old, junky knives are highly sought after, either because they are rare (being junk very few have survived), and/or, the collector is looking for a particular knife they really wanted as a kid but couldn't get one. Or maybe they had one but lost it, or broke it, or had it taken away by a parent/teacher/principal, older brother/etc. And now that they are grown up and have money they're willing to pay to get that long-coveted knife.
I've seen junk knives, made in Japan or Korea, that originally sold for $5 in Mexico sell for $400 or more on the collectors market for the very reasons I just described.
So my advice is to never throw away an old or junky knife without first finding out what it is. Chances are a cheap, junk knife is just that and nothing more, with no collector value, but then again, some day you might just stumble onto a cheap, junky knife that's worth hundreds. There are people who scour garage/yard/estate sales, flea markets, and pawn shops looking for such knives. And sometimes they get lucky. I wish I had a dollar for every time I've seen someone buy a knife from some elderly woman at a yard sale, a knife that had been her husbands, one sitting for ages in a trunk or the drawer of an old desk, and it turned out to be worth hundreds of dollars, or even a few thousand.