I have a line on a BRNO ZKK 601 in 243 Win. Date of Mfg is 1978. It still has the pop up peep sight. Overall it's in decent shape. The challenge is the barrel crown. It's a straight cut crown. I've never seen this type of crown before on a BRNO. I haven't seen a BRNO with a pop up rear peep sight either for that matter. The guy that's selling bought is used and says that is how it came. He mentioned that it has gone to a gunsmith to check the headspace and had the chamber tightened up. The gunsmith never mentioned anything about the crown. Just wondering if anyone has seen similar?