Seemingly very little information on these.

However, I came across a video earlier and just about wet myself laughing watching this guy's antics!

It was a foreign video so I couldn't understand him talking. The pistol was already in bits and he was at the stage of re-fitting the piston and spring.

The spring was crudely chopped at both ends with lovely, sharp jagged ends. No spring guide. He poured quite a liberal amount of oil all over the piston and a good measure more into the cylinder. Fitted piston. Then inserted spring. There wasn't a guide, just a washer at the back of the spring. Now, there was only minimal preload, but he has this washer resting on the spring and then compressing it with a screwdriver which is trying to slip off. He needs to get the washer far enough down so that the cross pin (Meteor stylee) can be inserted and he keeps making a proper old mess of it. The pin, once eventually inserted, just rests on the plain washer. Plenty of scope for improvement methinks, then, when I have a tinker.

I'm thinking degrease, clean, inspect seal and action accordingly, source a suitable spring and alter and finish properly, spring guide and top hat and then a more suitable design of retainer for the mainspring so that you haven't got a fairly narrow round pin up against the flat washer. Thinking along the lines of the part as fitted to a Supersport / Lightning.

Should improve this remarkably civilised feeling budget pistol even more.

Oh yes, at the end of the video he has a dirty great big hammer and isn't half whacking the hell out of the end plug to refit it!

Haven't laughed and cringed in equal measure so much in years!!