"U" serial CZ 27's

There was an interesting very early "U" serial CZ 27 on GB recently (U1087). I would hope one of you non-California guys picked it up.

The reason for this post is that this gun did not have the electro pencil serial on the left slide. The frame has the Eagle/4 stamp. The side plate has
the U serial. Typical for this variation the slide also does not have the standard CZ serial on the top. This particular gun came with capture papers which
corroborate the "U" serial therefore it most likely is not a fake.

I've noted that U1111 also is lacking the serial on the left slide.

Does anyone out there also have a "U" serial pistol without the slide serial? I'm trying to determine if there were actually two variations of the "U" serial guns. Early numbers with only the U serial on the side plate and E/4 on the frame and subsequent (more common) ones with the U serial on the side plate and slide with the E/4 on the frame.

I can post pictures if anyone needs to see what I'm talking about.

This information will be added to the next edition of my book if it is determined that there are two distinct variations.

"Muldoon"