poly will melt.... cotton will burn
I do not think that is a Travis top now that I see the stitching... the maker ran with the tension too loose. He was a bit of a perfectionist as was Jim Reed. But you never know.... do all the stiches look like that? It could very well been a home made top...
If it is truly canvas then you need canvak for it:
https://forum.ih8mud.com/threads/canvas-maintenance-oem-soft-tops.159334/
It does look more like polyester canvas imho, especially if it is a light weight. It is hard to tell regular canvas from a large weave polycanvas. It does look and touch...
The makings of that look an awful lot like a Travis top … he had made several tops
It could also be a one off… not all that hard just time consuming process