I made it there.....
Many thanks for all your help and support guys, without which this site would not be what it is.
For anyone who’d like to recreate the journey, it’s:
A1203 (The Highway) eastwards
Limehouse Link Tunnel
A1261 eastwards (or you could take the A13)
Leamouth tunnel / underpass (not sure what it is)
A13 eastwards, past Beckton, Dagenham (place of my daughter’s birth) and Rainham
Left on the M25 junction 30
Right on the A12 (direction Chelmsford) junction 28
You will then enter Essex..... after that you are on your own! Return post haste.
Of course, when I got there it was more than one picture to hang...
A picture
Two shelves, both level (naturally) and at points so exact it would have taxed the builders of the pyramids
Some decorative object, to be hung with the precision of a moon landing
A rail in the airing cupboard
Thankfully, I had anticipated that “Hang a picture for me, please” was code for “Do lots of other things, too” , so I had arrived kitted like Bob the Builder. Happy days.
PS Yes, I had my phone in my hand to take the pictures. Hang me, too.