I also wanted a "cleaner look" to the firewall on my ERA, and did not want the fuse panel and relays up there. I re-routed all of my firewall wiring to the inside of the car. I located the fuse panel, relays, wire harness, and MSD inside the cockpit.
It looks great that way, but is a pain to service - fortunately, there has not been much need to do anything with it, once it was set-up.
I even hid the hood latch brackets behind the aluminum firewall panel.
regards,
Jeff Burgy