Thanks guys, most grateful for your ideas. I tried to get on with Rockauto but found it utterly confusing. On the other hand Amayama was a model of simplicity and showed parts explosions which I took to Adam (MOT expert) who was able to say that the Suspension Arm bush part number supplied by Lexus was incorrect.
The leaking brake pipe part (90413-10234) was confirmed as correctly numbered and Amayama could supply it at a cost of £4.48 + P&P £7.29. Let joy be unconfined! The bad news however is that the incorrectly identified Suspension Arm bush is not so easily found. The parts explosion shows the part number to be 48780C (I think) but keyed into the Search box, the response is "Product not found" so I'm stumped.
I don't know of any Lexus experts in Bedford. A number of garages list the Lexus in their line-up of catered-for cars, but "I'm sorry, we no longer have Lexus expertise here".
With the level of MOT failure (dangerous defects), I'm no longer allowed to drive the car + the old MOT ran out yesterday 25th October + Road Tax & Insurance will also cease by the end of October: My options are somewhat limited, shortly to be non-existent. I'd still like to get the parts and hope, in the future, to find someone to do the work. It's my fault, for taking the car for granted for so long.