I can imagine how you feel about selling something the kids associate with some really good times. Just so I'm not to be confused with someone who actually knows about that stuff, my experiences are from what I've seen and not based on some school of higher education. Focus on the experiences of camping and they will come to know the Apollo in the same way. By the by, that is a sweet looking old coach. Love the looks of it. I'm sure your kids will have plenty of new memories in it over the years ahead too.
Stay safe there and Happy New Year to you and yours.
Ken