My comments below are not meant for Tom. Rather responding to other comments.
Picking up deck features and existing bores is good enough for most. But are you sure? What if your block is already at .030 and been decked. Do you trust the previous work?
You should start with the fundamental geometry which is the crankshaft main bores. Then if you need to make adjustment for casting shift, bore wear, angle decking, or whatever other reason you can do so with understanding of where you are from the crank.
