A lot depends on budget and how aggressive you want to be cleaning out the old stuff. I was lucky my PO was a BlueSea engineer and installed some nice stuff (see my photo in your other thread).  I still have a ton of dead wire behind that panel and am working on a sub panel for some other stuff I'm adding.   You can mimic much of how these panels go together by looking at their construction.  The CB are all Daisy chained in a bank using buss bars rather than wires and lugs. This makes it cleaner and more reliable.  One thing you don't see in mypanel is the traditional AB-both switch. That function has moved to a pair off switches on the pillar by the sink. This keeps the serious amps out of that space making it slightly safer ( 100A can still kill). 

Hope this helps   Let me know if you have questions

BTW there is another fuse panel under the seat just fwd of the nav station for 24x7 devices. Bilge pumps vessel monitoring.....

les

Tim,
I don't know if you want to get into a slightly larger project, but I re-used the frame of the electrical panel and made my own panel with dark smoked acrylic and new breakers (instead of fuses and switches).  It was easy enough to lay out the spacing exactly how I wanted it on a paper template, and then transferred the measurements to the paper backing that came on the acrylic. A drill press with sharp bits made quick work of the holes.  There's plenty of real estate on the panel for more circuits/breakers if you move the battery switch to its own panel nearby (I also added a dedicated engine battery switch).  I upgraded wire sizes where needed, and added a larger negative bus bar against the hull. I completely agree that you should try to get rid of the daisy-chained connections.  They are problems just waiting to happen. To connect the new breakers, I drilled holes in pieces of flattened copper tubing for each row, and ran a #10 wire to each row.  After the new panel was installed, I noticed that everything on the boat had more voltage going to it than before. Huge improvement!  I've attached some pix.  Hope this helps.

Tim,
I honestly can't remember as it was many years ago.  It must have been a few hours taking the old panel out and labeling all the wires, a few hours researching and ordering parts, a few hours designing the new panel, a few hours fabricating the new panel, a few hours fabricating a new battery switch panel, and more than a few hours installing the new panels. Kind of a wishy-washy answer, but that's the best I've got! 

My panel was also a mess after many years adding cables and more electronics. So last year I decided to totally rebuilt it.
total cost, including breakers, cables...around €1.000.-

Huge change and safety!

Regards

Eladio,
REALLY nice job on the new panel!  I feel kind of inadequate after looking at his pix, but I've attached the template I used to lay out my new panel.  One large file won't upload, so you have to stitch the four pages together. All items were obtained mail-order, except for the 3/16" acrylic, which I bought locally as a scrap piece. Tim, I hope this helps.