Most have the straight blade, which allows for some fore/aft movement and a small amount of left/right angular adjustment, but they can also be had with the "standard" fixed trigger blade. The actual trigger unit remains the same for both, it's just the trigger blade which differs.
Similarly I've seen standard LGV's with the adjustable trigger blade. In the abscence of original rifle documentation it is impossible to say definitively that an LGV was originally
Spezial or not, as the double spring could easily be fitted to a rifle which left the factory with a single spring.
The one exception is probably the UIT model, all of which appear to be fitted with the double spring and straight blade, as perhaps befitted their position as a top spec match rifle? Although Walther are notorious for unannounced small variations and changes, so anything is possible.
Page 7 of the manual indicates that the Spezial model is distinguished by the "divided piston spring".
I really like both my LGV-s and LG55, beautifully made and finished rifles which make 6ft/lb with the minimum of effort or fuss.