A quick on-line check for it shows you took a photo of it in its cleaner days and posted it up on Flickr. It is outside a house with what looks like a convertible on the driveway. Might that be the owning residence, or worth a knock on the door to make further enquiries? You may have done that, of course.
Local pub landlords, small car repair garages and MOT stations also tend to know owners of such vehicles. An email to the TSSC HQ might also be worth doing, if the car is known to them or the local Area Organiser, it may be possible to alert the owner that way.
Is there a recent Google Streetview image of it, showing it in another location along the same street, showing that it is a local resident that moves around?
Yes, That was the first house I knocked on, no answer, same with their neighbours.
That gold Merc is sometimes on their driveway, but I`ve never seen the Trummy on there, so not convinced its theirs, but, you`d think as fellow classic lovers, they`d know who`s it was.
I`ll be trying again tomorrow.