Mine was undersealed too but it was litterally a thin going over, and it was only the floor pan, stopped where they met the wheel tubs etc.
I got Tuna to do it when it was there some point last year, all the prop, exhaust and shields off and done properly, including all of the arches and tubs etc. Piece of mind and all that, TBF yours only sits in a garage at the end of the day