Thanks Kovid,
I'm not sure what I had in Tag Browser tab it could have been defaults - the tag browser looks OK though, I had hidden some categories, included some custom columns and changed presentation order they are all OK because they're not in Look and Feel
I thought I had changed Cover grid but that was when it was in beta, I barely ever use it, unless I hit its shortcut key inadvertently.
The order of items in Book Details has changed but I had not done too many changes there and its no bother to fix it - I'm good at clicking green arrows
The missing column icons are the only things that really concern me.
My back up is a synched copy on an external drive - I just tried accessing it with Portable and the Look and Feel settings are not as they were last night -- they are also showing the defaults!!
I am 110% sure the columns icons were there this morning before I hit the Restore defaults. I was pressing F2 on them to edit the My Comments cells. The defaults appear to be cascading through each database that I open.
I am pressed for time right now so I'll try to put the icon column rules back as they were by searching my own memory, chaley helped me implement a couple of the program mode templates I'll have to find the threads where we discussed them. And this time I'll back them up with screen shots, as I often do with other software.
Addendum #1 : I remembered that just before I opened the 'backup' copy of my C4B library with portable, I had opened the 'live' copy of C4B with portable - that might explain why...
Addendum #2 : found the threads where chaley pointed me in the right direction regarding custom icons and program mode templates.

MR Search and

again
chaley
BR