A PreB with an ORIGINAL blue finish would be a real steal to have. The problem is it appears that they came high gloss AND matte, so it would be hard to tell an original. If I remember correctly, they came to PX gun shops in parked, blued, and black painted finishes. I had an Army buddy who bought all three. I own the painted one today, albeit now in GunKote. The parked and matte blue were nice and preferred, as the painted ones came crappy from the factory - uneven, etc. I saw the others, and they were generally nicer.
I cannot believe I didn't get one myself for the 'mere' $225 they cost back then. But, I didn't have that much money then, and $200 then was still a bunch of money.
Back then, the CZ was full of machine marks, etc. They shot great, and had excellent DA triggers. My SA is still gritty, stages three different ways, but is quite shootable. The DA is beyond excellent. Of course, I've dry fired and polished is much over the years.