Actually, that was the very first thing I thought of. However, my situation was far more complex than presented in my post. I had just successfully done some quite complicated reorganisation of my data disc. Before I could initiate a new backup, I stuffed up. My analysis was that virtually all, if not all, the permanently deleted files came from the recycle bin.
It seemed it would still be faster & less fraught with problems to tediously look at the deleted files, and retrieve any relevant ones, rather than to start the data disc reorganisation from scratch. Given the nature of the disc reorganisation, this has proven to be even more tedious than first thought. But, with the job 2/3 done, I have yet to find any “missing” data.
My post was really just a forlorn hope that the was an easy way to overcome my stupidity. As such, & given that I will complete the task later today, let’s just call this post “Solved”.