[TYPO3] Partial upgrade problem

[McGonegal Robert]

I've upgraded v 3.8.1 to 4.1.5 on localhost (the numbers "4.1.8"  
appear when I login to the Back End). It seems to work ok but _most_  
of the Back End still looks like 3.8.. it has the new logo and the  
red kayaker photo, but old horizontal login page design, 3.8.1 icons,  
tan menus etc.

I deliberately installed v 3.8.1 because it's the only way I could  
discover to get the Quickstart site content in place to learn from  
(there is no longer a Quickstart for 4.1.5).

To start the upgrade, I recreated the symlink to point to the 4.1.5  
source code: $ sudo ln -s ../typo3_src-4.1.5 cms. Then I followed the  
upgrade directions at typo3.org:

In Install Tool--Database Analyzer--COMPARE
1. I clicked the checkboxes for "Add fields", "Changing fields", "Add  
tables" and "Remove unused fields" and clicked the "Write to  
database" button.
**There was still a heading "Remove unused fields" with a few fields  
still listed, so I did have to "Write to database" a second time.
2. Then next to "Dump static data"  I clicked "IMPORT"
3. I clicked the checkbox "Import the whole file 'static+adt.sql'  
directly" and the clicked the "Write to database" button
4. Then I clicked the checkbox "Clear be_users preferences" and  
clicked "Write to database" again.
5. Finally, after logging into the Back End, under Admin functions I  
selected "Clear cache files in typo3conf/" And I cleared my web  
browser cache too.
**When I went to view the Front End, it turned out /cms/index.php was  
linking to the wrong file, so I had to recreate a new symlink linking  
to the correct file.

I am busy reading the documentation but being a beginner and without  
knowing what's wrong, I hate to repeat the install/upgrade exactly  
the same way and expect different results. Can anyone suggest  
something simple I have missed or done incorrectly?

Thanks in advance.

Robert McGonegal