Howdy! sorry for the delayed response, I have been away getting married and on my honeymoon!
As for the rails for the warehouse, the yard ladder start and yard ladder extension line up perfectly with the warehouse (I build the warehouse specifically for these). that is what i used in the picture you see. MadMax is a little incorrect its not custom, but I love their idea about the old uneven ground with the fence rails!
Anyways, I suggest lining the extension yard ladder up with the bay on the end, then just line the yard ladder start up with the extension and youre good to go! Alternatively, you could build the yard ladder start and extension, then make all of the yard lines the same length and stop at the same distance using the straight pieces, then line the warehouse up with the end