Merbella's site never opened up properly I don't think. They're so swamped with business that they really don't need the site. She gets a slot open for a tail and it's booked in a matter of minutes.

If you're looking for a silicone tail, you might also be interested in Mernation, Finfolk, Mermaid Creations, Sirenalia, Purple Rainbow Tails, and Mermaid Jessica's tails (I feel like I missed someone in this list, but I can't recall who). They all have different prices and might be able to take your order a lot sooner.

As for Mertailor, recently what I've seen is visible monofins and messy seams (for full silicone). I haven't really paid attention to the old-style neoprin ones, nor the new hybrid skin+monofin ones.