Loetz? 14" Oilspot Vase

I'm a collector of art glass and am quite familiar with many artisans of the Art Nouveau/Deco era. I recently acquired this beautiful 14" vase. My research and knowledge is leading me to believe that it is a piece of Loetz. I would welcome any confirmation or comments as to my identifcation of this piece. This site limits me to four pictures. My flash has washed out the iridescence of the finish. I'd be willing to take more pictures and send them directly to any collectors interested in helping with the identification of the vase.

The actual color is yellow/gold with blue and purple iridescence. There is also some carmel colored streaking at the narrow neck and along the top of the vase. The pontil is polished and quite large. The top edge has an unusual fluting that is really stumping me.

Thanks for any help you can offer.