Hi Mel,
As of right now, no one can get anything from the factory. Everyone is just waiting for some sort of announcement that will hopefully announce a liquidation sale, so Sunline owners can buy up the leftover parts they need. Here's the good news: Most of the parts used on Sunline's are also used by other manufacturers, so they are available somewhere. Also, if you have something go wrong, just post it on this forum and there is a good chance that someone can help steer you in the right direction. Dealers can be helpful, but as the units age, they'll forget about what parts Sunline used and/or not have the part in stock any longer, as is the case with many older RV parts.
By the way, you bought one of the best RV's out there, and though you may regret it now, I'm sure you won't in the long run. Sunline's are known for their quality construction, so the chances of you having something go majorly wrong is pretty slim. You are in a unique position because your unit is, and has been, out of warranty. Most of the people on this forum were affected with having the warranties voided on their new units, but yours has been used and hopefully has its kinks worked out already. Now you'll just have age issues, which can be prevented/postponed with proper maintenance. This forum can probably answer any questions you have regarding cleaning, etc.
Good luck finding some owners manuals,
Jon