John;
Here is a pic of the profile of the Snyder shelves from a leftover piece I have. I have several dozen feet of their shelving and am very happy with them. As you can see, the shelf mimics 3-Rail track. Please forgive my feet!!!
‘And I have to agree with John H. - paying for them to do the cuts is well worth the cost, especially if you plan to fit the shelves end-to-end. Their cuts are clean and accurate.