Even if you were able to find a manual it would be so generic it probably would not help you that much. If you are wanting to understand the different systems in your RV and how to operate them a book such as
this one might be the ticket. I would suggest you run a vin decoder for the chassis to determine what year it is the year of the RV and the year of the chassis is not always the same. Then order a shop manual for it you can find them on line on CD for around $30.00 most shops will not have them for the older vehicle and it can save them time on repairs and that saves you money