In the Gunsmith of Grenville County book, there is a section where Alexander offers that the side plate panels on many originals he examined were often significantly thinner than 0.25" and thinner than the corresponding lock panel. He provides several measurements from originals, many of them in the 0.140" - 0.190" range. He then asserts that "...it is obvious that the side plate panel is never as thick as the lock panel, even taking into account that original locks might have had thinner bolsters than our modern reproduction locks." Instruction is given to start with a side plate panel thickness of 0.25" and removing wood from there.
On two particular builds, I have attempted to follow this criteria and made the side plate panel less than 0.20" in thickness at the breach, and have lived to regret it. In both cases this caused the width of the wood along the tang to be significantly less on the side plate side compared to the lock side and thus asymmetrical. While I understand that symmetry of the side plate and lock panels is not important when viewing the gun from the sides, I have never seen any photos of originals where there was obvious asymmetry about the tang when viewed from above. Most I have seen have an equal thickness of wood on both sides of the tang.
Am I misinterpreting Alexander's advice and instructions, or how is it that the side plate panel can be thinner than the lock panel without appearing that there is unequal thickness of wood on both sides of the tang?