Model Die Casting's Roundhouse line had quite a few similar kits in their "3 in 1" line. They were basically various parts from their inventory which were to be used to kitbash into the kits subject.
I made many of the "3 in 1" kits, and in doing so I learned a lot about kitbashing as their instructions were pretty good. For me at the time re-starting out in the hobby, the plans, details, how-tos, and materials list were a great help to me. Most if not all of the kits were marked "additional supplies required by modeler", which was really true.
Many modelers assumed they could make a Jordan spreader, a railroad steam shovel, the fire train, etc., from the box contents. I picked up some of my kits from disillusioned modelers who gave up on trying to do the kits.
This is how the kit for the steam shovel turned out, following their instructions:

After I built the model I discovered it was quite a way from the prototype, so I rebuilt it to look more like the real ones:

It was fun while it lasted!