Aqua, the search does not work all of the time. I have been to that area recently on the survey. Try Google Earth and look for a neighboring district then try that on the site. In this instance click on 'maps'...pick the top one '1:2500' and then 'Stafordshire', I think it is Stafordshire. This will get you to a grid system of maps and you can pick one with maybe Aston on it and then work your way up to Gravelly Hill I think it was; changing maps till you get there. On the top of each map there is a number which coincides with the grid and the numbers on the grid will show as you run your mouse over it. So that if you needed the next map up say, look for the one above the number you just looked at. Where you want I seem to remember is close to a map edge and you may have to go back and forth. No matter, you can open two windows. Good luck.
ps, if you don't get there let me know.
pps. the smaller scale 1:10000 maps work too but they are not as clear.