Hi Guys, thanks to the various replies I've had to this post I now understand how this works to a far better degree than before. I hadn't realised the nav aid data was contained in the scenery files, that accounts for the original installation using a nav aid database dated around 2004. At that time Lydd did have a DME and NDB but no ILS. I came across a program (World FSXP3D package https://www.aero.sors.fr/navaids3.html) which updates the nav aid database to the latest airac cycle. After running this, FSX now has up to date nav aids including Lydd and Southend. I've been able to successfully fly a full instrument approach into both airports without a hitch. (Nil wind you understand ) So I'm back up and running, now I just need to tune the controls a litle bit to make things more realistic but delighted to have finally got somewhere at last. Thanks again to everyone for your input.
I wonder if my instructor would accept a printout of the flight analysis in order to sign off the approach?