Allow me to start this post by saying that I am not an expert on this topic and have no special insight into the heritage of this model. That said, what follows is the culmination of much careful research. Given the lack of a good knowledge base on this topic, I have had to make inferences and educated deductions where necessary. I present you my thoughts and ask you to draw your own conclusions. The M481 is a little understood model, likely owing to its relative scarcity. Just how many were produced over its run is unclear. The model was initially released by Pelikan in 1983, largely for the export market, and it appears to have enjoyed only a relatively short production run. Released just one year after the re-introduction of the M400, it seems safe to say that it can be considered the predecessor/prototype of the M200.
One of the confounding factors surrounding this model is the fact that the early, pre-1997, M150’s were released with labeling/packaging that stated ‘M150/481.’ In actuality, it appears that the M481 was already being phased out at the time of introduction of the M150 and M200 (1985). It is my understanding that the 481 designation was an early name for the M150 but when the success of the, then newly released, M400 became apparent, Pelikan decided to build a range of pens around that line. In order to avoid signficant confusion, the 481 nomenclature was dropped and we were left with the M150 as we know it today.