Those are pricey. Better price is rebuilt at a good shop in your region.
Did you first read any postings in the Mitsubishi-Satoh section yet? Plenty of answers over there.
Now, the other question is, what engine do you have in the D1600II because that and the D1800II were known to have two different engines, the serial number is the divider for these models.
Download the
MITSUBISHI-SATOH HISTORY REV 2.pdf
in that same sub section. There on page-13 is your answer too.