David .Noted and understood.
The Frontline Conversions kit does seem rather expensive for what it is and not too straightforward to fit to the BRA chassis.
There is a firm in the States called Classic Conversions offering a simpler 4 link coil spring set up for the MGB back axle that does not need a panhard rod and may be cheaper subject to shipping costs.
The latter design uses the front leaf spring fixing for one link and the inner links are angled in to hold the axle in place.
I am going to investigate further as I am still interested in getting rid of the cart springs.
Best Wishes DavidA