Old postings
You need to cut off the reply responce time to inquieries to about 1-2 weeks or maybe a month after the origina or last reply. Other forums on the web do this, as a responce to a paragraph initiated 1-2 months ago, or last year are seldom read by the person who posts, nor understood quite some time later.
If a post gets a responce 1-2 time per week, let it run. There are a few forums on the web that have a time limit such that if no additional replies or comments occur after a week past the last one, no more replies are permitted. It physically stops any more replies. If there is an ongoing conversation that is OK, but if beyond about 2 weeks since the last reply, the content of the original conversation gets meaningless and lost. The computer, internet and CAD oriented forums elsewhere are like this now, as often time the subject gets turned away from the original inquiery and become meaningless chit-chat.
Just as old advertisements for items are meaningless, so are old inquieries or posts, and as such should not expect a responce from the original person posting.
Leave the post and replies in the archives so that they can be reffered to, but do not permit an untimely reply.
Wm.