First thing is to find out who at the perspective targets handle PR, second is always ask first in private business if it is OK to send a presser to them or it will more then likely end up a quick glance or spam delete depending on how you issue the release.

Second is always send 2 copies, one to the perspective person who handles such things second one to their assistant. just in case it is overlooked by the person it is intended for.

Best way to find out who a contact is is just call the companies and listen to the automated directory or ask the operator who handles PR while giving out little or no info, usually the phone person will not even ask you anything

BTW you stated it is for a small industry are you going to follow up on the pressers?