Hmmm, well you must have had the good one. My Champagne Ir3 Fly went 309, 275, 300, 100, nothing. To be fair it ended up making a nice mantlepiece ornament in my first flat.
Mine would have been similar to yours when it was new.
WDPs design and quality of machining was the same on all guns. Nobody, not even WDP can produce guns to that standard anymore.
However, I was smart (experienced) enough to know WDP didnt set their guns up right from the factory.
I spent a good few hours with the pressure gauge, grease, the manual (and Johnny Rice in the background), fixing all the problems before I even aired up my gun.
Otherwise it would have probably ended up as an ornament like yours.