I'm sure there are more 1/2 frame guns out there than previously thought although still scarce. The last few stock books show 1/2 stamped for frame size however I can't believe all these were true 1/2 frames. I'm guessing that their 1 1/2 frame stamp broke and they never made a new one.
Here is a link to my 1/2 frame VH 2 barrel set in the Albums section. The original barreled gun is all Meriden made in late 1937. A few months into 1938 (repair codes) it was sent back to Ilion for the second set of barrels made in Ilion. Both barrels were 28", original choked M/F and the Remington barrel Cyl/ImpCyl.
http://parkerguns.org/forums/album.php?albumid=358