What you posted applies to all the MMP patents, but not the 148. The 148 filing date is 7/29/98, therefore this applies.
CONTINUING APPLICATIONS
A patent granted on a continuation, divisional, or continuation-in-part application that was filed on or after June 8, 1995, will have a term which ends twenty years from the filing date of earliest application for which a benefit is claimed
It was a normal expiration since the 148, claimed the benefit of the 8/3/89 filing date of the parent application.
Opty