Sorry, haven't checked in for a while, for various reasons, CV19 lockdown being one. Since posting, I've been suffering with a bad back which an MRI scan reveals to be caused by a buggered lumbar spine, so now waiting for a hospital referral to see what can be done to sort it out, so I guess I should also put my aspirations in this direction on ice for now. (Plus I have an unsailed Beneteau 21.7 sitting on a pontoon that I can't get anywhere near until lockdown ends). However, once I get over these little issues, I will definitely follow up these suggestions. Many thanks.