Can anyone help me identify this gun sight?

[JonnyBowler]

Hi Mike

Sorry, I should have stated the size!

I don't yet own the item... I'm considering buying it from a militaria dealer as a 'momento' of my grandfather's WW2 service in the Royal Artillery on Bofors guns - hence the reason I need to be sure it's from a Bofors.

The dealer sent me the following shot of the sight on a wooden bench, which should give you a better idea of its size:



Apparently the circle diameter is 19cm (7.5") and it stands 28cm (11"), so I'd guess it's the right kind of size for an artillery piece?

Below are some of the photos I've found (some from this forum!) that show Bofors L60s with similar sights - but, to my eyes, the proportions look different or the details are too obscure to be certain:










Maybe it's from a naval Bofors?

Thanks

Jon

PS - I don't suppose you're a relation of T.D. 'Tommy' Calnan, the WW2 PRU Spitfire pilot?