RustE-
That was the exact information I was hoping that someone on the forum could answer as I could not find it either, including multiple searches for it in alternative sources than the 2 sites you looked at as well. The only function that I'll be using calipers for is reloading. There is a branch of MSC local to me, so I could pick up a 1" Mitutoyo block for $35-ish. If the Wen 123 blocks are going to be within the tolerance of the digital caliper (+|- .0005), I would opt for them due to cost as I am not yet into a level of precision that would really justify the additional cost. Going to send an email to Wen to see if they can tell me what those 123 blocks tolerances are held to by QC during the manufacturing process.