If anyone can advise me of what is the best way to go about selling my property
Well you could build a facebook page dedicated to the manor, upload lots of good quality photos of the property, plans, surrounding area. Write a more detailed description of the property, perhaps charting the renovation, if you have before and after photos from when you originally bought it that would add interest. Make sure the text is Polish and English. Then get your friends and colleagues to like your property and to ask others to buy it or like it, until hopefully someone makes an offer, perhaps you could ask people to MAKE ME AN OFFER, have a certain target in mind and if someone offers you what you want bingo.