I know it's been almost 20 years since you bought your AV but the factory never installed a factory Snugtop onto their AV, it may have been a dealer installed option or you got it from Snugtop or one of their dealers and had it color matched.....
As far as determining a market price for your AV it as usual depends on supply and demand. Sites like
www.kbb.com or
www.edmunds.com can help you get a price based on condition, options and popularity in your area code etc.
There are threads that talk about posting photos to help you do so you can go several routes but easiest way is to make more posts since the site is set up as a safety from spammers. You also have to have more posts to list in the For Sale section I believe too.