The coordinates listed above will take you to a place that should be on the list of Historical Landmarks. It's the only one left in town, that I know of. Walking in here is like stepping back into the 50's.
It's a drug store with a sit-down soda fountain, which seems to be heading towards the same fate as drive-in movies.
You do not have to buy anything here to complete the cache. All you need to do is count the number of swivel seats at the bar and add that number to the number 150 to get the complete northern coord for the physical cache.
This relic of the past is closed on Sundays.
The physical cache is located at
N 29-28. 150+ # of barstools
W 098-29.550
Minoxidil is for hair loss, which you might need by the time you get through pulling your hair out looking for the sign in only cache. No pen.
Stay on the street side of the grey brick wall where the final cache is located. No need to trespass around on the other side.
PLEASE DO NOT REMOVE THE CONTAINER FROM ITS LOCATION:!
Open the container, remove the log, sign it and put it back in WITHOUT moving the container!
If someone removes it and puts it back the wrong way, it won't last long. Thanx 
San Antonio Area Geocachers