I nave a Brno 581 that began going fully automatic a few years back. A new sear and sear spring were in order.
Finding parts domestically has been a chore so I emailed CZ knowing that for a time, they made the CZ-511 which was identical to the 581. At the time, the person I contacted said that he thought they had some parts and instructed me to call the factory. Time slipped away from me and a half a year passed by the time I called. The person on the other end of the line acted like I was insane for even asking about 511 parts so I hung up and sent another e-mail to the plant. The person who responded apologized for the abrupt phone response and said that he was thinking that he had some parts someplace and would get back to me. Months past.
Last week I got an email from the man at CZ saying that he found a small packet of parts for the 511, consisting of two hammers, three sears, 4 sear springs and two sear/trigger pivot pins and that he would be sending the entire lot to me Fed Ex, free of charge, as they no longer cataloged 511 parts in their inventory. The parts arrived Thursday last and the ol' 581 is back in business.
My hats off to CZ USA for some exceptional service.~Muir