I'd sell. You're on Odessa road aren't you? Stow brothers have agreed a sale this week on Chichester rd fully done and extended but no side return and I'm told it's very close to the 750 sticker price. Seems nuts to me. I sold mine for 702 18 months ago when the market was red hot.
It went on the market in early March but we had a buyer after the first viewing and they're a cash buyer, which has sped up the process somewhat.
Similarly, the place we're aiming to buy is from a chain-free seller and six weeks has been mooted as a possible timeframe.