The 1st Stage brings you to the former site of Bishop's Inn. This busy roadside hotel was a 2 story brick and stucco house built in 1813 by William Bishop. At the time, Belair Road was a busy thoroughfare that connected Baltimore City with Jerusalem Mill in Kingsville.
The inn was sold at public auction in 1845, most likely to a man named Joseph Brooks. In 1876, Dr. Abraham S. Baldwin purchased the house. That same year, a tollgate opened up on the nearby Baltimore and Jerusalem Turnpike, thus adding to the number of travellers who accepted the inn's hospitality. In 1908, both the inn and the tollhouse were purchased by the Goettner family. By the 1980s, the home was owned by Howard Harple. He sold the property to KFC in 1985. The Perry Hall Improvement Association fought to save the historic structure, but their efforts failed and the building was bulldozed a few days after Christmas in 1985. If you are interested, there is a video of the demolition. The first couple of minutes and the last couple of minutes are worth a look.

1st Stage is where Bishop's Inn once stood. When at this stage, you would have been at the back of the house pictured above. You will need to visit here to obtain information to find the the 2nd stage. At posted coords, you will find a large green box. On the back of the green box is a 2 digit number followed by a 3 digit number. The 2 digit number is the year the box was placed here, ignore that number. Add 57 to the 3 digit number, call your total ABC. Then subtract 106 from the 3 digit number, call that XYZ. Plug in your totals to the coords below to locate Stage 2. I have provided a geocheck for you to check your answer.
N39 24.ABC
W076 29.XYZ
Stage 2 is a small container with room for SWAG and TBs. It is located in a fairly common hide in the woods. Hint is available in the geocheck.
Congrats to AllIsVanity and GnomeGCer for FTF even with my coords that were off by about a half mile. They bring their "A game" everyday.