Hi Martin,
I just have couple pages scanned from this Wente-Lukas book that a friend sent me. I would like to own the book, but very hard to find a copy I think and I would not be able to read the text.
I agree that if the lizard is mostly found to the south it makes sense the sword is from that region. Here is the wikipedia page:
http://en.wikipedia.org/wiki/Ornate_Monitor
Or could the skin be the Nile monitor lizard? It has a much wider range it seems.
http://en.wikipedia.org/wiki/Nile_Monitor
Best,
Iain