My view is that it's a Willie Manson weight and may well have been from his "William Manson Paperweights" period of the early 1980s. It's certainly not a Paul Ysart one and I don't think it was made by Willie at the Harland studio. It matches well to others illustrated in books and appears to be a "Magouillat Lizard", as Derek has said, but each of those weights would normally have been signed and dated.
That there is, apparently, no signature cane is interesting. Perhaps it is possible that the central grinding had removed the identifying cane ... but if so, the cane would have been very thin to be completely removed without causing a deep hollow!
I hope that if the weight is subsequently repaired and repolished it does not alter the look of it too much.