This is a long shot, but here goes. I recently completed N scale layout N52 nfrom the Atlas book, 4th edition, printed in 07/83. I hope someone`s familiar with this layout as I want to use the spur that is on the outside to start my addition. I plan to start by putting in the start of a 2.8% grade off this spur to go into the new addition. Any hints from the pros out there on how to put in the addition and be able to bring it back to the starting point? Maybe I should just start from scratch? I am not able to build a layout from my head but need a diagram. Thanks.