Take a look at the sign again at the DMV. My understanding is that it now says "no conceal carry". The last time I was at Henderson DMV there was no sign on the door at all. As far as Henderson goes, it is A-OK for you to open carry in Henderson City Hall. You are correct that it says LEO only, yep, the same old sign. I am guessing that they have no intention of changing it but wish to leave it up to fool people. They however are NOT enforcing it. My opinion is they are playing games. Be assured I have carried in Henderson City Hall numerous times now with absolutely no problems. I believe others have as well. If you look in my thread about the fight with Henderson, you will see a copy from ACA Lentz stating they can't enforce the old policy. I carry a copy in my wallet just in case I run into someone trying to enforce the old policy. You will also look on the "rules" sign at Henderson parks and see that the line about no firearms and weapons is taped over. My neighbor works at one of the parks and when she found out it was me that forced the issue, she explained her displeasure with me, oh well.
Welcome to the forum, open carry and the area.