A complete 2552 trinket set in black would obviously be useless as the pattern on both trays (brush and pin) is on the bottom. This must have been an experiment, possibly even without the knowledge of the management! It would be very easily done if a shop making black plinths was next to one making normal candlesticks. The weights of the two articles would be roughly the same (important for the size of the clay "nose" or "moil" on the end of the gathering iron). The plinth gatherer could easily pop one or two gathers into the candlestick mould by mutual agreement between the shops. Just why do this, goodness knows! Perhaps too much beer (official after 1100 am).