Nice to se an update! we have all been there trying to patch work baseboards and in time it's not worth it as it cause's problems and N-gauge isn't forgiving enough. The key is solid framework with holes in it for wiring to pass, good base for your track work and if using point motors make sure they don't interfere with any cross beams. looking forward to see how you progress, It's a lot of work but worth it in the end!