IvorMog, I did think that your expansion tank looked a tad too "elegant" to be a standard Morgan fitment... (-:

Thanks also for posting DaveW`s layout drawing of the Roadster`s cooling system, though I note yet another term for the remote tank has crept in....When the term header tank is used in a discussion I automatically think central heating....(-:

Also from DaveW`s diagram I noted... heat exchanger... What is that items purpose in the car...?

Happy to wait patiently with fingers crossed or any feedback on the description of recovery tank design and operation in an automotive situation.