The l-pad It's the resister symbol thingie with the 5 ohm/5W that's right before the tweeter on the schematic. The "fuse" is the "poly switch" I think, and if so it's sandwiched in the circuit board assembly, the l-pad(s) may be as well.
To access the crossover you may need to remove the woofer, the crossover board MIGHT be either glued and/or screwed in place. I see them for sale all the time on ebay so they can't be that hard to remove.
I had a problem with one of my Infinitesimals, even though I knew the EMITs were good one had lower high range output than the other. I even put a note on the back of it saying so. Maybe it was not functioning but it's so close to the mid/woofer I thought it was, and my hearing does fall off above about 10Khz.
Not sure why I took it (the Infinitesimal) apart but I pulled the EMIT a month or so ago, cleaned the push on connectors from the crossover where they push on to the EMIT and just like that output was restored. I used a gummy putty like substance where the leads from the crossover pass through the faceplate, maybe some of that gummy substance was keeping it from making a good connection. Or possibly it was dirty/corroded or just not making good contact.