Not sure what this is, but does not look like a Greeves frame

[John Wakefield]

https://www.carandclassic.com/car/C1427917

Part of the John Clark estate
Offered at No Reserve
Believed to be a Greeves frame fitted with a Villiers 250cc engine
Partially assembed, parts included as pictured
CMRC certificate dated 1999
Recommissioning/ rebuilding will be required
Viewing is advised

[KevinLS]

Looks like a Ducati frame

[KevinLS]

I did some digging. I'm pretty sure it's a narrow case 250 Ducati frame although it has had some bracing added. A pretty rare special, although I've been reminded that Colin Aldridge rode a Ducati-Greeves in the early 70s. The shark fin shows that this one has been prepared for the track much later than that, although to my mind, a bit of a futile exercise. But then again I've spent my life exercising futility.