Got an email tonight from Spurl, just more than 48 hours after uploading of my bookmarks, saying that my bookmarks have been uploaded and are ready for use.
That's great news because I was about to give them up. I found something good about them which is that they retained the my bookmark structure. Whereas in Furl all my 800+ links are all grouped under "imported bookmarks" and I'll have to manually move them into "My topics" for logical grouping.
Another reason, perhaps, for Spurl for spending so much time before making links available to me is that they have analysed them, see below screenshot. Oops, lots of them are broken.