Land Survey Complete & Survey Marker Details

We received the completed survey back on the property yesterday morning.  The property is technically two tracts which are 9.849 and 20.780 acres for a total of 30.629 acres.  What does not make sense is the surveyor says the total land area is 30.70 acres.  We questioned it but he confirmed it is correct even though the two tracts don't add up to the total.

We were not required to obtain a survey but decided to do so and split the cost with the seller.  The seller had a plat from 1974 which showed the original division of 200 acres into smaller tracts.  The bank would have used this but we wanted to make sure everything was correct and have markers placed everywhere.  We figured we would want it done at some point and right now could negotiate the buyer paying half.

We made a quick stop by the land today as we were in the area.  We obviously could not enter but I wanted to see the survey markers.  The surveyor added a couple of new markers and they look like the following:

He found existing markers in locations which look like the following.  They are a little small and look like he had to dig them up.  He put a T post at each spot so they would be easier to see.  

The survey indicates he put a few markers with his surveyor code on them along the back side.  We don't have access to the land yet so I can see those.  

I've heard of people putting the survey markers in concrete so they are not easily moved.  I'm not sure if this is a good idea or not.  I'd hate to cause a problem by tampering with the surveyor's work and have a good survey to handle any dispute.  However, putting them in cement would not be all the difficult.

At this point, we have almost everything we need to close.  The title company is just getting some final details from the bank.  We will then be able to set a closing date but unfortunately it will not be 5/31/16 as originally expected.