Renewing these seals is a no brainer when replacing the bodywork with new or refurbished components.
The FJ1300 is all about comfortable, long distance touring, and yes sometimes it does rain!
New seals will help keep the rain from penetrating the cowling joints giving the rider a much dryer and more pleasant riding experience.
Other seals you may wish to consider:
3P62842810
3P62842900
3P62844E00
3P62846F00
3P62821800
3P62822800
Cheap enough to buy spares for future use, while they are still available. Add as many items as you wish to the same shopping cart, new bodywork retention studs and anti-vibe mounting components for example, and still only the pay the same fixed price shipping cost.