just to add: arrived Monday, fitted it, works fine
thanks all
The flaw, as ever, is that the web, or rather websites, don't actually deliver what they appear to offer - it's still down to the humans to do the critical bits. My guess is that in the case of spares it's not profitable for anyone to actually have accurate databases of car parts. In this instance it was a Suzuki part fitted in a Subaru. Most breakers don't cross reference between the two, although it's more accurately sites like breakeryard that should be cross referencing: you searched for this part for car A but no one has any, however an identical part was fitted to car B and they are all over the place.