Welcome aboard. The vintage forums here are an excellent resource with lots of knowledgeable guys if you fancy getting into vintage Breitlings.
There's no minimum post limit to PM a member, and you can do so one of three ways. Firstly (and the easiest way ) is to find a post in any thread by the member you want to PM, and then click the "pm" button at the bottom of their post. The second way is to click the "new messages" link next to the "Logout" link at the top left of the screen, the click the "compose message" link on the left-hand side and enter the members name in the "username" field before clicking "Add [to]". You can then type your message. The last way is to click the "Members" link under the Google search on the top right of the screen. Then click "find a member" on the far right and enter the username you want. The user's record will appear at the bottom of the screen and you can then click the "pm" button next to their name on the far right.
