Keith, You can find Murano pieces which can appear similar. A couple of characteristics you will find in these pieces that the Murano foil pieces generally do not have are:
1) Optic ribbing in the body of the vase. Both this piece and my Rosa pair have similar optic ribbing in the glass, and many examples I have images of have the same characteristic.
2) A pontil. The Italian pieces which can bear some resemblance to the Loetz decor are generally found with flat ground and polished bases.
My Rosa pair were actually listed and sold as Italian glass, and when I purchased them I was unaware of the Argentan decor, and I had been looking at Loetz and other Czech glass for years..... It was only 6 months later that I figured out what they were. When I first got them I knew they were not Italian due to the pontil they had, and the general "feel" of them.
I never in a million years expected that I could buy another example of the decor on ebay, especially in a listing that had Loetz in the title!! You never know where the next treasure is going to come from..... And I am a firm believer that if you don't look, no matter how unlikely, you will never find anything....
Based on the stuff you do come up with, it would not surprise me if you uncover one somewhere..... You seem to have a great eye, strong persistence, and some good luck.....
Craig