This is a very good analysis. It remains a very peculiar collection of ballistic facts but I think there are some reasonable conclusions we can make:
- The weapon and ammunition were non standard and subject to bespoke alteration on the individual items.
- The alteration process was amateur - the crimping for example was not done with the best tools for the job. This suggests a workshop without high quality equipment, but where the workman had a degree of skill and know-how in terms of how to acheive a workable result with sub-standard tools.
- The weapon and ammunition were highly likely altered in the UK - the particular alterations were specific to the challenges posed by the British legislative regime for handguns.
- The result would have been a very poor, unreliable weapon. But capable of lethal effect.
Together this points to garage-style small-scale workshop producing activated or reactivated weapons for the British criminal fraternity.