Hi Guy,
Here is a pic of the pistol dismantled. It is unusual in the piston having a welded-on protrusion for engaging with the sear. The only other pistol I can think of with such an arrangement is the Webley Whiting.
The pistol is quite well made with some attention to detail not found in many medium- priced break-barrel pistols. For example the stock retaining screws are bedded into nicely countersunk grommets, the cylinder plug is integral with the solid spring guide, there are no rough welds hidden under the grip, and the bluing is good quality.
On the downside, it is a bit top heavy, the grip shape is ugly, and the trigger is harsh. It is easy to cock. For build quality, I would rate it on a par with the Slavia ZVP and not quite as good as the Diana 5. Streets above the Voere LDP4, which IMO is by far the worst air pistol ever made. For me, the Jung Roland is an interesting and quite rare collectable and I am glad I acquired it when I had the chance.