The Lange 1A (ref. no. 112.021) was one of Lange's first limited editions. 100 were made. I believe #1-20 had yellow gold second hands and the rest (#21-100) had blue steel second hands, though some hands may have been swapped along the way. The dial is solid gold, and the movement includes solid gold parts too (escape wheel, pallet cock, escape wheel cock, balance cock).
In person, it looks spectacular. It's actually not too blingy -- at least, not in my opinion.
Something (a "discovery"?) that I just now realized about the Lange 1A ... On the time subdial, notice that the four Roman markers "XII"/"III"/"VI"/"IX" are applied, and the eight other 5-minute markers (diamond-shaped) are printed. I don't think Lange ever used this combination of applied and printed markers on any other Lange 1 model. Usually the Roman numerals and 5-minute markers are either all applied or all printed -- consistency among all 12 markers. I could be wrong about this, though.
Also, from my old post 16 years ago: #39/100 (caseback # 117439) remains stolen and was never recovered.