I don't know much about line locations, other than the minimum distance from the rails, as prescribed in the D&RGW Standard Plans. https://www.drgw.net/gallery/v/DRGWStandardPlans/drgw_standardplans_p290.png.html I largely followed proto photos for placement.
I wouldn't blame you if you didn't add the lines Hemi. Not sure I'd have the patience for it either and then you'd get into the issue of always bumping them when cleaning or working on the layout. Imagination is a strong modeling medium.