Yes, MKII Swift.
MKI had exposed mast base and open deck to the main beam.
MKII mast base enclosed and main beam covered over by decking, creating small storage areas.
MKIII alloy beams and trampoline
MKIV last of the line and an upgraded MKIII

You might find this useful:
Prout History



John Alani
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Stealth F16s GBR527 and GBR538