Dear Mncad;
You and I have similiar problems. I have had to model bent railroad tracks for use as guard rails and running rails in a diamond crossing. All of the rails have many holes required for bolting them together, some of the holes are pendicular to the web, like yours, others go through the web at a crazy angle.
I used sweeps to create all the rails. The holes are dimensioned in relation to the line segments that make up the sweep path. The holes are all drilled prior to bending so their location have to accurate.
Fortunately I can measure off the old existing diamonds in the field to find where the holes should be, then I place the holes in the part by a bit of trial and error. I open the plan view of the diamond with hidden lines visible and then manipulate the individual part sketches untill I get the holes where I want them.
I make individual part files of the rails in the straight condition (Yes I know, I could use 1 part file and 2 configurations) and add in shop factors to compensate for the stretch in the rail caused by bending.
It seems to me you are going to end up doing similiar things to create your part.
Best Regards
Adrian D.