Yes I did try PartZilla and several other online retailers. Depending on the decal needed and the year of the bike some decals are available while others are not. Unfortunately the specific decal that I need for my bike is no longer available.
I also looked at what is offered from grafnet.eu. However, as is explained on their website, grafnet does not offer exact reproductions of the OEM decals. Rather they are a high quality representation of the factory decals. So you can not replace only one ... it won't match. You need to replace every decal on the bike. This is not what I have in mind.