A friend of mine came into possession of a CZ 24 pistol that was made in 1928 I believe, and it passed into my hands because its in really rough shape. Doesn't have the history that your 27 has, but its got a unit marking of some sort. I think these are neat little pistols, love the fact that the sideplate has all the internals underneath for easy maintenance.
Cool story about yer grandfather! Imagine finding a relative in the middle of a war like that!