I have already out-line the instructions I will be following. I "X" out the parts I will not be following with a blue "High-lighter". I have the old Tamiya 251C, the newer Tamiya 251D, the AFV 251D, and now the DML 251C.
IMO-- Nothing is usable from the OLD Tamiya 251C except maybe the front wheels (thicker then AFV), and the rear seats (different kind).
The 251 by AFV is a "D" and the 251 from DML are "C's". The AFV lower chassy is very complicated. Also be careful cutting from sprue, some parts have attachment points that do not show well on sprew (I cut a few off by accident--not hard to fix but still a PITA). The running gear alone is over 30 pieces and that is only the track part not counting wheels!!!