BM disassembly might not work depending on the valuation type.  (You don't get to choose the cost tier).

This won't correct production history, but:

• IM Adjustment down (for the bad amount), posted, then Adjustment up for the correct amount.
• GL journal entry to move the $ difference from the IA account offset to whatever variance account was overstated during the WO posting.

BM disassembly might not work depending on the valuation type.  (You don't get to choose the cost tier).

This won't correct production history, but:

• IM Adjustment down (for the bad amount), posted, then Adjustment up for the correct amount.
• GL journal entry to move the $ difference from the IA account offset to whatever variance account was overstated during the WO posting.

I will try this one, as well in a test company.