[kezo]

Looking on living made easy website, they mention John Preston Healthcare, but, their site shows a 10day lead time. Also on the Living made easy site(below) other similar options include Alber E-Motion M25 and Alber E-fix E35 & E36

https://livingmadeeasy.org.uk/category/access-and-mobility/wheelchairs-scooters-and-buggies/power-assists-for-manual-wheelchairs