Traces of used download sites

A few days ago I spent hours searching many websites (such as Amazon UK, ClassicsOnLine [Naxos], Linn, Arkivmusik, etc.) for a particular music recording. I found it on a site — call it X, — downloaded it, burnt it to a recordable CD, then discovered that it suffered from the common fault of a badly edited join between two tracks that are supposed to run smoothly into one another. I had also downloaded something from another site (let's call this one Y), which was perfectly all right. Having visited 8 or 10 sites, I got completely confused, complained to Y that their recording was faulty, got them confused as well and got a promise of a refund from them which is even going to include the small cost of my wasted downloadable blank CD.

Having discovered my confusion, I now want to contact X to tell them about the fault. But by now I had deleted the faulty files from X (but still have the faulty burnt CD). Unfortunately, having visited so many sites, I no longer remember X's identity. My browser's 'History' facility is no help because of the number of sites I had visited, some of them twice or more. So my question is: is there some hidden place in my computer that retains a record of websites from which I have actually downloaded something, not merely visited them?

Many thanks in anticipation of the unlocking of a secret store of information.