This excellent observation about the hardened pegs set into the LGV's breech block to eliminate side to side play was made by member 'dvd' on the airgunbbs.com here:
"The fork in the cylinder's end through which the breech block swings, is effectively wider at the top than it is at the bottom. I measured mine and it results that the top opening is 17.96mm and the bottom is narrower at 17.50mm.
So those two solid pins protruding slightly in the block, serve to lock (wedge)the barrel securely in a keystone fashion and eliminate any side to side movement. The detent takes care of any up and down movement. I find Walther's system better to break open the barrel since no slapping on the barrel is involved.
The inclusion of the two pins is a simple but highly effective solution to eliminate barrel side play. I suspect each gun's lock-up was fettled by hand to achieve this perfect lock up because if the pins were too wide by a tiny amount, the breech block would not close closely enough to the transfer port resulting in a leak past the O ring. On the other hand if they were slightly too narrow, they would be ineffective for their purpose and the barrel would close like any normal break barrel without the enhanced lock-up. So they had to be just right."
With thanks to Mark for these pics, who says:
"A rare one this,more so than a LG55 DST as these rifles were banned from competition use,just as Walther made the DST trigger unit available for the LGV.
Stamped into the breech just above the serial number and next to the 'F' in a pentagon are a couple of what looks like shields one of which has '84' in it. Then there is '.705.' next to that.
The breech unit is not drilled for fitting open sights.
The standard rear diopter is fitted, although the front unit is fitted with a post foresight...
Standard match stock with really nice butt pad and a wood plug just behind the end cap that was fitted to strengthen the pistol grip."
Note that the breech block is not drilled for and open rear sight.
The first series of pics are of a 'UIT' stocked version of the LGV which was transitional and spanned earlier and later models. This is a Spezial. Pics courtesy of Mike D.
The second series are of a later LGV stock with sloped forend.
This rare boxed LGV sold on eGun, the German auction website, in March 2013: