I'm looking at doing my first exterior make over too. Although I think mine has 9 more years of oxidation than your finacee's!
Poliglow and RedMaxx floor wax seem to be very popular "waxes". Similar effects it seems, but the floor wax is dramatically less expensive, if less proven, and possibly prone to yellowing in some cases.
Poliglow Products, Inc.| Manufacturer of Poli Glow, A New Concept in Boat Polish
Shop Red Max 128-Oz. Low Maintenance Floor Finish at Lowes.com
Now proper buffing is a mystery to me. People seem to rave about The Bar Keepers Friend, as a cleanser/polish.
Bar Keepers Friend | Cleaning Products | Household Cleaning Supplies
Not sure if the powder or liquid have plusses/minuses for our use.
I've typically used Mothers and Meguiars products on my cars, but the small spots I've tried with that type product indicated I might want something less subtle for the badly oxidized
Scamp. For the much newer trailer you're dealing with something like that may be enough.
I'm sure there are many other options, but those products seem to be very popular on here. I'll probably be picking up some Red Max, simply because I'll be in a Lowes this week, other than the internet I don't know where to get PoliGlow.