I whole heartedly agree. Check deed calcs for any/all rational interpretation of the call for half. Even consider half by slope distances. If anything fits the forest fence within a few feet, then I might just hold the fence. I sure would hike that line to find any blazes or evidence of owner actions, even fence mending. Evidence of time/money spent by the owners is on the list of relevant items to add to your search for Best Evidence.
Then I would review all the evidence and alternatives as to interpretations and actions with my client. At that point if the client wants, I will monument my soltion and record the survey.
If they don't want mons, the balance on you work for fees is $XXX. I will hold on futher work until you have decided otherwise.
If they just want time to think things out, fine. If they want to run to a lawyer, fine. They do not have to do what the Dr. orders. They are not required to do what I might say is best for their wallet.
SURVEYORS!!, SURVEYORS!!, We don't need no STINKING SURVEYORS!!!!!
But what any owner past or present has done with or without surveyors to pace out via their understanding of the boundary and fit or plant a post or many is relevant.
In this case the fence was originally built long prior to the division. It was a convienience fence. The question becomes, at the time of the partition, would any form of Half fit the fence? It might be enough to offer as proof of intent to use the fence.
Wouldn't be the first time what they did to determine the Half line on the ground and conveyed to their Attorneys got stripped from the Deeds to "half" with nada further info. It's a latent ambiguity. That's what lawyers are taught to do. Ambiguities create future fees
Add up and use best evidence that clarifies the intent of half.. Bring clarity to their vague understanding. Monument and record your solution and put the lawyers to rest.
Common sense, but I have been surprised how many surveyors don't do that. It has always seemed more ethical for me to simply talk to landowners on both side if there is a boundary issue. One of the frequently overlooked things about this is that if someone goes out and flags a line and surveys it on land that another thinks he owns, the chances of amicable settlement of the line may be significantly reduced.