Input on a "Temporary" Shelf Track Plan

[foulrift]

On my switching layout I use a combination of a runaround track and a switchback to spot cars.This way I do not have to move a car from another industry in order to spot a car. I have one long lead that holds 3 cars one of which is a tank car which as mentioned may sit for a couple of days before it is unloaded. I also have a couple of non industrial spurs where I can put cars that are waiting to be spotted. At present I am trying to come up with a simple method for switching,something like Jack suggested.
Anyway-have at it and have fun with it.
Bob