I don't know really, because I didn't see it.
It's been common to see Triple Ganzas, which are three metal tubes welded together using metal strips. The tubes didn't touch, allowing for a fuller resonance.
I'll do some searching to see if I can find a picture ... or even better, a place that sells what you are looking for.
EDIT:
Here's a photo of a Double Metal Ganzá ... is this it?

If so, go to
www.brazilianpercussion.com ... they have quite a few sizes and varieties to choose from.