Many thanks all it is indeed the Autoland v21 from FS2004/FS9. I did indeed go poking around in the panel.cfg of the 164 liveries package for the default 737 and it was installed as part of that.
The confusion was that I’d spent a lot of time using the default white skin 737 hence why I hadn’t noticed this as it only appears on the repainted versions.
Not sure if it’s been tweaked to work with FSX as it was more CFIT than landing. I’d set up a decent landing configuration before intercepting the glide slope and activating, it reduced the speed applied the right flaps and lowered the gear but proceeded to throw the plane into the tarmac without flare far too aggressively.
I don’t know others opinion but it feels a bit like cheating anyway. Considering there’s already the ability to use ILS down to 1000ft and then take over manually, this just seems like it takes the fun out of the landing.
Many thanks for your replies.