Thanks McCreed and Bakersdozen.
Right back at the start of the build I determined that the bridge works as both top-loading or string-through. Photos on the kit page show top-loading. I decided on top-loading to keep things simple. I also decided way back forever to drill after the finish to reduce the risk of water getting into the holes and cracking the finish. At the time I was planning on wet sanding. As it turns out I didn't wet sand so could easily have drilled first. However, sticking to the plan means masking with tape and drilling carefully, which should get the hardware fitted without damaging the finish.
The finish is super hard now, so I don't have any fear of the tape itself causing damage.