Hi all. An update.
In the end I purchased a 70mm A/F socket and a 1 metre breaker bar. First attempt to remove wheel nut resulted in the breaker bar deflecting like Robin Hood’s bow (appropriate perhaps as I am a MSCC Sherwood group member!). In the end I resorted to the trusty mallet and hammer supplied with the car. I can tell you it took quite some effort to shift the week nuts. I torqued the wheel nuts to 120NM with a large torque wrench the gave them a further quarter of a turn with the socket and breaker bar. They are very tight indeed and as they will continue to self tighten. I am confident this will be a good working solution.
Well worth removing them for an inboard fettle and a wipe with an ACF50 soaked rag though. Once a working garage solution was derived I found I could remove, clean and refit all four wheels in a couple of hours (with the aid of a 2 tonne trolley jack) which I think is quite reasonable. Wouldn’t do it more than twice a year though.
Don’t over do it, as you can ruin the threads! Also, I think acf50, wonderful though it is, is not the stuff for splines and the mating surface betwixt hub and wheel; a generous greasing is recommended otherwise you will get clonking when changing direction snd worn splines.
