I thought the purpose of these set-ups was to catch strangers, not locals; as a local, you should know what the limits are in any case. That way the fines come from people passing through and are applied to the town/police budget, thus limiting local taxes.
But yes, fight the ticket provided you weren't in breach of an overall limit you should have known about. You need a good map of the road you were coming in on, with pointers to where you were, where all the relevant road signs were, and where the cop was. You need photographs, with the dates on them, showing the part of the road without signs, the road where the signs were and the sign obscured by overgrowth. Have a record of what the whether and road conditions were when you were stopped (clear skies, daylight, visibility dry road, etc.)
You need to practice explaining your case before the day, so that you have a clear and logical explanation for the judge. This is a technical case, so you probably don't need the abject apologies and personal justifications, but keep an eye on the judge's attitude just in case.
If this is set up to make cash-cows out of passing strangers, the police might cave when they see you are a local who is fighting it - they won't want a court ruling that will stop their cash-cow working in the future.
I would hope no-one is likely to take fighting a ticket against you, even in a small town. They might be amused you fell for the trap in the first place. If you make a habit of falling for it, you will certainly become known as the idiot who keeps falling for it.