Stand down...

With SQL 2008 reinstalled, this time with BOL, I ran the SP1 .EXE ... and it ran through to completion.

Tada!

Personally, I hate problems which "go away" because I can't...

Well...my first honest response was "What difference will that make?" but I'm the newbie here, so I tried it.

I haven't tried to manually extract the contents of the SP1 .EXE...