How should I resolve a deed conflict?

I have a problem with my deed and my neighbors deed having conflicting information on them. �My deed says the original property was 100 foot frontage by 175 deep. In 1966 30 foot in depth by 100 foot wide was sold off the back of the property. �Recently my neighbor down the street bought the property and his deed say 50 foot deep by 100 foot wide. This is a conflict of 2000 square feet. Is it like that's there is a typo on one of the deeds? �I have contacted the planing and zoning office and the tax essment office as well and they have conflicting information as well. Not to mention we are both being taxed at the larger property sizes. �Do you have any information that may help