Well, I have done the not so dirty deed and rebuilt with DW. It has "successfully rebuilt a new optimized directory" repairing errors, scavenging, etc. along the way.
Obviously it could not do all this without causing me some confusion from time to time - that goes without saying - but there I've said it, so now I feel obliged to explain. grin
On the initial report it advised me (underlined too) that "It is recommended that you preview the replacement directory." So, I did, but to be honest I didn't know/understand what I was looking for/at despite consulting the various docs on the DW disc.
At the end it asked me if I wanted to save the report, at the same time as stating "DiskWarrior found problems and the report was not saved. The report is a useful reference." It still gave me the option to save, which I clicked, but the next window had "save" greyed out. crazy
At this point I quit DW and the computer restarted. As promised it has placed various files/folders at "the root level of the disk": Damaged Files (containing a 4KB alias), MoveRename (contains nothing), Rescued Items (ultimately nothing), Trash 2 (also ultimately nothing). Can I assume that I may delete these seemingly innocuous files/folders as I cannot find any advice in the Manual to this or any similar affect.
I'm sorry for going through an idiot's (me) guide to what is/was a comparatively straightforward "task", but neither age nor health (or wealth come to think of it :() seems to be on my side nowadays.
Thanks for "listening". Regards. Mike