There is no proper place for that. Big players like Vogue could do large-scale info-rich articles on brands, lines, bag models and trends, but they don't. And until they refer to the Monogram canvas as 'cowhide' (as they did in an article in December), I don't consider them serious. So basically nothing comprehensive is out there. What is left are the official books Vuitton sells, their magazine, the older SAs who where there in the 00's and 90's too, and there are some black-belt vintage shop owners out there who sell trunks and classics and know a lot! But it takes years and years or reading and research to put the pieces together.
That 'decline in canvas quality' is a myth made up here on the forum. Both the canvas and the hardware are constantly researched and improved. In some aspects, they are different and might feel worse (for some), but in many others they are improved and way better and longer-lasting than the ones made decades ago.