Well done Banzai, I think you have nailed it down!
Another one to keep you occupied!  

This one is Becontree Heath, Dagenham (1968) and it's in TechniColour!

The Box on Wood Lane in Becontree Heath, Dagenham - K41

That said, to get the same POV the yardage given in the Met List is way off. It says it's supposed to be 30 yards west of Rainham Rd, but it's actually more like 100 yards west of the roundabout.

Street view --



URL:  http://maps.google.com/maps?q=Rainham+Rd+N,+Dagenham,+Greater+London+RM10,+United+Kingdom&hl=en&ll=51.561198,0.151277&spn=0.00683,0.033603&sll=51.6073,-0.300638&sspn=0.001876,0.0042&t=m&geocode=Fa6vEgMdrm8CAA&hnear=Rainham+Rd+N,+Greater+London+RM10,+United+Kingdom&z=15&layer=c&cbll=51.561194,0.151287&panoid=fZYr8j5c0FiZhokHDxt1IQ&cbp=12,91.3,,0,4.22

As with your car's side view mirror, "Objects in your Street View are closer than they appear." If you zoom it you will see the buildings are nearly perfectly lined up, meaning the Box was probably about where the electrical enclosure is behind the lamp post.

Are you sure it's not more like just after the crossing? It looks a lot closer in the photo than the electrical box on streetview...

If you pivot the street view you will see that the original photo was probably taken from the eastern corner of the Becontree Heath Bus Station (S-bound).

Right side of frame --




Looking at the photo again, the traffic barriers were there at the time. I bet the old location for the street lamp post was were that different colored patch of concrete is immediately next to the electrical box in the POV street view. Counting barriers in the photo (there are eight) would take us to just past the 4th barrier, or about half way between the electrical box and the path to the crosswalk.

Hmmm, I'm not so sure, I think they have moved the road somewhat....

I could be mistaken...

I thought so as well at first, but looking at it I chalked it up to Google Street View screwiness. Those wide angle lenses can really play tricks on you - things seem to recede into the distance much, much more rapidly than they really do.

To double check, I just now looked it up on Google Earth and the roadway and roundabout are in the same positions now as they were in 1945.

Ok, well I was wrong. That's ok, I'd rather throw something out there and have it proved wrong than potentially miss out on something. I just thought the path now, looked like where the road would have been then.

Glad you can see where I was coming from though

Box Site street view --



Most likely between the two barriers to the left of the trash bin. Note that even if you measure from the western tip of the triangle that splits the road at the roundabout, this would make the Box Site a good 90 yards west, or about 110 yards from the roundabout itself.

Box Site Street View URL:  http://maps.google.com/maps?q=Rainham+Rd+N,+Dagenham,+Greater+London+RM10,+United+Kingdom&hl=en&ll=51.561071,0.151652&spn=0.001707,0.008401&sll=51.6073,-0.300638&sspn=0.001876,0.0042&t=h&geocode=Fa6vEgMdrm8CAA&hnear=Rainham+Rd+N,+Greater+London+RM10,+United+Kingdom&layer=c&cbll=51.561135,0.151476&panoid=2_trxVUdJaEvMB6B4hKJYQ&cbp=12,63.96,,0,17.89&z=17

I really see what you mean about the lenses Google Maps are using.... It does look a lot closer in this last shot.

A couple more pics of this Box from the 60s:

From 1966, before development --



Blowup --



And from 1966, when the buildings were being erected --



Blowup --



OS maps:

1938-1939 (marked P.C.B. at centre of frame) --


1960 (marked PCB at centre of frame) --

Here's another one of K41 Wood Lane, Becontree Heath (c1950's) 
By the colour of the box it has to be post 1952ish.....

PJ

Thanks for posting peterjohn.

Showing Three Travellers PH and Dagenham Civic Centre

Larger map:


Enhanced

K41    

A.R.W. Siren    

08-Oct-34    

14 Sep 70   

Wood Lane, north side 30 yards west of Rainham Road North
         
District:     Becontree Heath    

Subdivision:  Ilford


8th May 1960 ( © Paul A. Bateson ) :