Aftermarket or retrofit fuse box?

I will be using an under dash harness in my 65 Dart wagon from an 80s Dodge Mirada. It uses the blade fuses and has separate circuits for pretty much everything. Am also eliminating the ammeter and going with a voltmeter. By eliminating the ammeter I will have 3 individual 12 gauge wires running from an aftermarket fuse/relay center into the car via the solid bus bars on the junction block. I added a third bus bars to the 2 already on a stock bulkhead connector. I swapped the Mirada bulkhead connector for the 65 Dart connector. The incoming wires go to the headlight switch (1) and (2) to the ignition switch and will be protected by suitable size maxifuses in the relay center. Am also going to use the Mirada steering column since the under dash harness is already set up for it.

If you're interested I have a fuse panel form a later year A Body - think it's around 74 or later - and it has plenty of fuse capacity.