A Tour of England

I am a senior single and would like to do a tour of England. Not just the usual London, Stonehenge, Avon...blah blah blah. Been there, done that. I would like to see estates from the Regency period and other historical sites for example. Can anyone recommend either a small group company or someone who does such trips for two people? Also ideas of what might be exceptionally interesting and fun? Thank you