Sticker Removal on Front Cap

I have a 10 year old Jayco TT that I plan to sell. I put about twenty smallish 'places we've been' stickers on the fiberglass/gel coat front cap that I would like to remove. Some have completely or partially peeled off and left a hard residue.

The entire cap isn't in perfect shape having been used and stored outside for almost 11 years, so I don't want to try to buff out the area where the stickers are since that would make it too obvious. Also the large Jayco name and logo could be a problem.

Does anyone have any experience or ideas on how to remove the residue from these stickers? Naptha might work, and paint thinner, alcohol and acetone are possibilities but I don't want to damage the fiberglass and make it worse. The exterior of the trailer isn't in great condition, but I definitely don't want to make it worse.

Thanks in advance!