Hi Len, as you already know my van was made by Adria and I have the exact problem as you
Looked at it a few weeks ago and that was as far as I got, but came to the conclusion that yes all 48 rivets would have to come out. The actual seal just looks like a flat piece about 25mm to 30mm wide? This is riveted and sandwiched between the main body and the hinge then tucked around the hinge whilst putting the locker door back on, will be a two handed job to hold the locker door in place until you get a few rivets back in. And there in lies another problem the pop riverter i have may be too big to get between the body and the lip around the locker, will have to get it out and double check.
Oh and a word of caution as we will be fitting back in to "plastic" so to speak make sure the rivets are not too tight as the first one on mine has always had a crack in it.
Oh and if you source the seal let us know where from, Cheers. Maybe a standard supply in caravan shop?