...John, I noticed on that page that they recommended fusible links on all wires leaving the junction. Why would you want fusible links instead of fuses when fuses would be easier to replace if you had a problem?
That borders on a religous question.
You are entirely correct in that a fuse is easier to replace, probably easier to troubleshoot, and much more common and available. The downside of fuses is that they do not tolerate momentary over currents very well. For example my electric fans have an internal resistance of about 0.25 ohms leading to a startup current of 60 amps. Now this current does not last very long as once the fans come up to speed they draw only 15 amps. So using a fuse you need a 60 amp fuse and 60 amp wiring which is way overkill for the normal draw of 15 amps.
The fusible link on the other hand deals with momentary surges like this very gracefully and is only triggered by constant over current. The downsides of the fusible link are much the opposite to fuses with the addition of being a potential ignition source when they blow.
There is also another alternative and that is the circuit breaker. GM put one of these on our cars but built it into the headlight switch (which is why they will sometimes blink). The advantage of the breaker is the potential to be reset when the over current condition has been "fixed".
I believe that MAD also discusses fuses versus fuse links on their site although with the volume of great stuff they have I do not remember exactly where.
Now getting back to the original topic...
I have done something much like you are asking about. I sourced a "distribution box" from a later Ford Taurus and mounted it up on the DS core support in my '68 El Camino. I made a contoured bracket that uses original factory core support holes from the regulator and horn relay to mount it and it hides and just about looks like it belongs there.
The beauty of my solution is that I have loads of additional maxi sized bladed fuse slots to hang stuff off of *and* several (like 7 or 8) relay sockets to deal with horn, headlight high, headlight low, fan high, fan low, and whatever else I come up with. I even have a few regular sized fuse slots plus a 175A maxi fuse in the box. I think I hung the original fuse panel off of a 60A maxi fuse. I have maxi circuit breakers on the headlight relay power supplies.
I used a pretty big hammer on this problem, but a smaller setup could use one of the 4 or 6 fuse weather proof fuse panels as an expansion panel. With these you are pretty much limited to 30A per circuit and 60A (or something like that) total. There are wire current/size charts out there to specify what wire size you need to feed the panel with.