garden wall against steps - footing question

[diffets]

We have a stepped pathway leading down the side of the house to the bottom of each garden between us and next door.

The small garden wall (3 concrete blocks high at most) is built right on the boundary and against the steps if you see what I mean. The lower portion of this wall has been knocked over and I want to rebuild it exactly as it was but I will need to re-do the footings for this lower section as it looks as though the blocks were laid onto no more than 2cm (yes, 20mm!) of concrete on top of the compacted soil - probably the reason this section of the wall failed.

My question - I won't be able to place my 4" blocks in the centre of the 4"-6" deep 12" wide new footings as shown in all the guides. The wall needs to be against the steps, on the edge of any footing I can put in. How do I proceed, what amendments will I have to make to the footings in width/depth to allow three courses of 4" block to stand on the outer edge of the footing? I need an "L" shape rather than an upside down "T"

Please advise.

Many thanks,

Stefan

[welsh brickie]

3 blocks high= 675mm from the foundation to the finished block height.You will only need a small foundation 200mm wide 100mm thick is adequate.
What about paving slabs on edge? if your stuck for width, 900x600 will do, you can bury them in the ground and concrete them in place and they are only 50mm thick.