I have the original aluminum case from my 69's M20 four speed. The part number stamped on the case is 3925660. I know this aluminum case would be valuable to someone doing a restoration on a 68 or 69 four speed car, because I hear these original aluminum cases are very rare in un-broken form. I haven't got the first clue what this case is worth. do any of you resto-buffs know how much I should ask for this case?