Has anyone seen these lately?

Sherry

Beryl's.com has them under silicone molds, exclusive, leaves.
She has two molds. Hope this helps

Nicholas Lodge has them or he did at the convention.

Yes i have a source for you, it is http://www.sugarpaste.com
You will need to call them since the acanthus molds are not on the catalogue or website yet. The lady you should talk to is Elizabeth. She is a super nice lady and can help you out with your order.