Ah ha, you’ve all jogged my memory. We have a thread (which I started - doh !!) about them. Although the one I’d seen was different. And I still don’t make a connection with their name for some reason. This one looks more detailed. Shall post this one on the Benchmarks thread below. Thanks all. Viv.
I’ve found these two; one at Snow Hill, the other at the Old Bill and Bull pub (formerly the Hay Mills Police Station). Photos from the Geograph site. Are there others in the area ? And presumably they’re marked on OS maps. Viv
birminghamhistory.co.uk