Before I go hunting, this is what comes off the top of the head. As always, the final choice is yours as to how far you go (if it looks right etc...).
D1502 has different cantrail grilles to the bodyshells produced. 1500-1509 had a single vertical bar in the centre. The rest of the class has extra bars fitted to their grilles. Boiler-wise, this one had a Spanner MkIII fitted so, it had a round exhaust.
D1673 (I think) was air braked from new so would have had Serck louvres from Day 1 (if not, very soon after). Clayton boiler on this one so big square exhaust.
D1611 here. Three part grilles and a Spanner boiler (round exhaust).