The yellow NDCF wagon in 42101's photos is an ex G wagon (GP, NOHF and so on). It can be recognised by the recessed side panels that remained when the sides were reduced in height and the distinctive frame. The number however is probably a "new" number in the W ("way and works") series rather than its number in the capital stock (although many G wagons carried low numbers).
Most of the other wagons in the photos are modified BDL/BDX (NOBX, NOBF) wagons, some of which retain the corrugated side panels (but have plain panels in the door spaces) while others have plain panels throughout. These have the distinctive underframe that deepens to twice the depth at an angle at the first external pillar on each side. Again these have numbers in the "W" series (often in the 2500 series) rather than the 28 000 to 33 000 series they had in the capital stock.
The height of these wagons was reduced for the spoil traffic when it was realised that wagons with full height sides were frequently overloaded when filled with spoil. The final "H" in NDCH indicates that these wagons were heavier than standard freight wagons when fully loaded. Many Hunter Valley coal wagons have a similar final letter to indicate 120 tonnes fully loaded. The reversion to NDCF might have indicated a reduction in the permissable load for that wagon.
The short orange wagon with platforms at each end is a former BD (NOAF) wagon, as indicated by the corrugated side panels and the short central section of deeper frame.
I've never seen an NOEF used in a spoil train, nor have I seen one coded NDCH or NDCF. But they could have been used. They would stand out, being about 35 feet long (like the NOAF) but with flat side panels, compared to the 45 feet NOBX and 40 feet long NOHF wagons.
A number of NDCH wagons (ex NOBX) were sold to CFCLA for conversion to container wagons, and the new numbers should be found on their website.
A large number of NOBX wagons have been used for concrete sleeper trains, some with fixed racks and some with sleeper racks on container frames. Other NOBXs have been converted to carry two spoil containers. These are painted orange and can be seen in 42101's photos as well.
All of these wagons have "new" numbers in the "W" series (although most don't carry the "W" anywhere).
A number of former NOBX wagons are being converted to rail train use at Goulburn at the moment. Some of these might have been spoil wagons.