Merry Christmas and welcome to the forum Mark!
Sweet new rig. Looks in good condition overall. PO put some work into which shows care. Tires
, floor etc. Siliconing the seams is a popular fix for replacing the seam tape. If you search the site you'll find some topics on it. Maybe you could just redo it but a better job? If the insulation is ok it's worth keeping. Heating/warming, stretching and re-gluing is an option. I bought the seam tape from Scamp
. They have good products and ok prices but after you ad shipping and customs to Canada it's not worth it. I found almost the exact same tape at Home Depot.
Search google with "fiberglassrv.com" + your topic in the search bar and you'll find tons of articles on this site about any kind of reno. Plus I'm sure I'm just the beginning of helpful FGRV.com people to pipe in.
Enjoy your Christmas present,