Hi Dave,
Here is my ex-spurt (the drip under pressure kind) opinion. I milled my own wood out of yellow cedar, bought the stainless strips and bolt set from Mar-K, and marked the holes in place. The Mar-K instructions were fantastic and they were a great outfit to work with.
I would have been very uncomfortable drilling the holes without marking them in place. Here is the process I used for the install. The first step was to slide the edge boards under the angle strips to mark the bolt holes. The cross sills were attached next using measurements supplied by Mark-K. Middle boards get bolted through the gap left between the boards so no drilling here. And finally the bed to frame bolts and offset washer holes were traced from below removed and drilled. There were some measurements given here to use as a double check.
