If possible please post/attach an photo of the Engine Serial Number "LAY 537525".
That is not a "casting" code. Casting codes are cast into the block when the block was cast at the engine factory.
You Block Casting Code and a Block Casting Date are identifiers of the block.
That "LAY" Engine Serial Number code was stamped (by a human being) into the block of the engine when it's original vehicle was being assembled. It was not uncommon for the human to use an incorrect die/stamp for a letter that looked like the correct letter.
