what car is this for

[Morgy]

while rooting around in my boot if found this?
   
   doesn't look like a 289 unit?
   
   IMG_4970 by mark.morgan07, on Flickr
   doesn't look like a 289 unit?

[BE774]

Spare wheel clamp for Aces, Acecas and Cobras?

[AC Ace Bristol]

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   .
   Morgy
   
   
   Not a standard fixture, but as BE774 suggests, a suitable home made  device to locate and secure  the spare wheel in the boot of  a Ace, Aceca or early Cobra.
   
   The correct aluminium retaining threaded item is very hard to find, Maybe someone can cast a small batch [?][?].
   No, don't look at me I did the fuel caps.....[;)]
   
   Keith

[Morgy]

IMG_4971 by mark.morgan07, on Flickr
   
   IMG_4969 by mark.morgan07, on Flickr

[Morgy]

So this would have no place in an AC 289 sports?