I have added two companies, one is European. This article is also helpful: https://www.ricksteves.com/travel-tips/transportation/booking-a-car
We are staying at the Strady Park Hotel and will be having our reception dinner at this location. It is within 30-45 minutes of the castle and a 3-hour train ride from the London airport. I do not have a block room as if yet but, I will keep everyone updated.
As appreciated as your gifts may be, they are not needed as you will see. The presence of our family and friends will do, and make our day special too!
January or February at the latest.