Yes, Continental went out of business quite a while back, as in 10 years or so.
If you have one that's working,or even close to working, you are probably a sole survivor. If you have one that isn't working and never did, you are among the many that bought these systems.... so don't feel alone.
I don't want to be the bearer of bad news here but a having a manual isn't going to help you much. In my opinion, the systems are junk. Don't beat yourself up trying to make it work, scrap it and get a new one, from a more reputable company with a good track record.
I've talked to many owners and replaced quite a few of these systems, so I speak from my own experience.