Here are two more roads where I have seen woodblocks in man hole covers within the street.
First to Old Street. There is one outside No.1 on the north side at the junction with Goswell Road. There's only a teensy tiny bit of wood visible but, if the Islington ones are indicative of hoe today's road surfaces will erode, we'll hopefully see more of this one in due course:
And there's another one east of there. You'll find it on the other side of the road within the bus lane outdide No.134. Tho this one doesn't look like it will be there much longer – the road is in a poor state and the man hole is sunken, so I rather assume that the next re-surfacing may well see this man hole disappear:
My pics are the ones where the wood blocks are wet. Top left pic shows the view looking west past St Lukes (you can just see its spire above the trees). The fourth image, bottom right, was sent to me by Dave Brown who alerted me to this in 2021, and shows the blocks dry.
Next, across the river to Woolwich. I was strolling along Powis Street, the main shopping thoroughfare, when I spotted this one outside No.29-31:
There are bound to be others in the Woolwich area, so I will be back on a wood blocks hunt there soon.
Do let me know if you've seen others – my A-Z of London wood blocks can be found here.