Hi. Not sure what the BGA TP for Shenington is. Is it Enstone? If so there is a NOTAM re aerobatics at Kidlington. If you are looking at the plot, you should always refer to the printed text for details, since sometimes the plot gets confused if the coordinates are out of sequence (the butterfly shape around Enstone is a case in point). The data comes from the standard NATS PIBs and the airspace shown is from a file which is publicly available - I don't have the info immediately to hand but can post it later.
You can relate a plotted NOTAM on the screen back to the text if you hover over it - it will pop up the reference. In fact the reference is also shown on the printed plot.
The main restrictions this weekend refer to Fairford and Farnborough.