The illustration of the razor, seems 'suspect' to me ....nearly all the descriptions state the blade is almost the same size as the handle. In use the 'razor' is used 'double handed' . The design illustrated does not fit this criteria and looks like an ordinary barbers razor ...but scaled up. The handle is too wide to grip comfortably. After all the blade would not have to be totally enclosed within the handle ....just the edge.
A practical 'Amazonian razor' IMHO would be similar to a Panabas ....with a 'folding' abillity.
Kind Regards David