Right, a load of sightings in diagram order :-
Units on following dates
Diag .17/12/13 . 20/12/13
No01 .609/618 . 606/607
No02 .618/609 . 607/606
No03 .6XX/6XX. 605/614
No04 .615/6?? . 619/620
No05 .???/???. . ___/___
No06 .???/???. . ___/___
No07 .619/6XX. 6XX/6XX
No08 .6XX/619. 6XX/6XX
No09 .6??/615 . 620/619
No10 .6XX/6XX. 614/605
No11 .625/___ . 610/___
No12 .608/623 . 609/617
No13 .617/622 . 611/621
No14 .621/624 . 622/624
No15 .611/620 . 604/6XX
No16 .620/611 . 6XX/604
No17 .610/612 . 6XX/6XX
No18 .612/610 . 6XX/6XX
No19 .???/???. . 608/618
No20 .???/???. . 618/608
No21 .624/621 . 624/622
No22 .622/617 . 621/611
No23 .623/608 . 617/609
No24 .605/___ . 612/___
XX01 .613+614
XX02 . . . . . . . 613+615
All these were seen between 17:17 and 20:26 unless otherwise stated.
___ means no unit as per diagrams.
6XX means no unit even though there should be.
6?? means I possibly missed it !.
??? means not observed.
XX01 was 18:21 West Croydon to Epsom.
XX02 was 17:12 West Croydon to down and 17:55 return to Victoria.
Diagrams 01+02, 05+06 & 19+20 are not expected to be 377/6s yet (20/12/2013 but note some appearances.
Diagrams 05+06 & 19+20 if observed was later at 22:15-22:45 approx.
Diagrams 05+06 were formed 456+455+456 on 20/12/13.
Diagrams 07+08 seem to be bad performers.
Totals/figures/summary :-
17/12/13 noted 18 377/6s in use, 604, 606 & 607 spare/not-seen, 601,602,603,616 & 626 untested.
20/12/13 noted 19 377/6s in use, 623 & 625 spare/not-seen, 601,602,603,616 & 626 untested.
I say 601,602,603,616 & 626 are untested but the arrival of 616 & 626 at Selhurst must be imminent and all are now delivered (as far as Stewarts Lane).