Turns out the game writes a new table to the SRAM (offsets 20000 - 20FFFF) that the game references at offset @207C28. The table contains the line data for each team (NLC, SC1, SC2..etc), which is the roster number (in hex) of the player on the team, 6 people per line. The data is the same numbers found in the team data sections, except this new table in the SRAM adds a byte to each value, so it's twice as long. For example, the team data will show 011214 (goalie, LD, RD...etc), but the new table is 000100120014. Anyway, the table in the SRAM stops at the 28th team and my original intent was to find the code that generated this table in the RAM to "tell it" to go to 34 but I couldn't find it. At least not yet.
So as a band-aid, I included an expanded table in the ROM, and changed the offsets that referenced 207C28. The player cards AND names work for all 34 teams, but the names that show up during the home screen match will be incorrect after someone edits the lines since the table I pasted is static. The SRAM is still written, so it's easy enough to flip the offsets back to the SRAM, which I will eventually have to do since I believe the game also uses the SRAM for line changes data.
So as of now I have a playable 34 team ROM, with editable logos and banners, and players. (YAY!)
Things I need to continue to work on, expected level of difficulty:
* Teams 29-34 won't work with line changes (MED/HIGH)
* Add music for new teams (MED)
* Find out how to make playoffs work for teams past 26 (MED)
* Decompress some additional graphics like the splash screens, timer logo, John Schrader, etc. (LOW)
* Figure out the season data stuff -- calendars, teams, matchups, standings, divisions, etc (HIGH)
Moving along...