I recall reading years back of Corvette guys doing this type of thing...not sure what the process was but I think was used to 'show' the original stampings on restamped engines?.
Similar to what your saying, the castings still retain the imprint of the original stampings deeper down and although decked, still shows when magnafluxed or something similar?.
Haven't heard anything of it in recent years...perhaps since restamps are allowed w/ the 'Vette crowd?.
~ Pete
