I have everything on the schematic now that I think I will need for the TTL PCB.  It only takes 8 pages and 36 TTL chips.  Creating a PCB from the schematic shows me I have quite a lot of work ahead with routing the 16-bit memory bus and 8-bit data bus along with the clock and control signals.  I will definitely need to go to at least a 4-layer board.  Hopefully not more or things will get expensive.  I figure I can stick to the simple rules of top layer traces run vertical and bottom layer traces run horizontal.  And then lots of vias.  I figure I will run the traces through the center of the board horizontally.  And then pull them off up and down to the chips.  

I'll probably also add some debug features later - maybe some LEDs on the busses to make everything look good.  And I still need to add the breakout header for the bus.  So it's not 100% done, but the essential components are on there.  I will upload a preliminary schematic to the project as a snapshot of where I am.