SPO, Earlsfield

Some of the signs I've been posting so far this year came with a bit of history about the product(s) or the company. Unfortunately today's sign has faded too much to identify the company in question or the nature of its business.

S. P. O.
&
..ons [?]
Actually there is another, earlier, sign on this wall but I can't make anything out the few letters that can still be spotted here and there. Traces of it make the 'O' look like a 'Q' (then only a 'R' would have been missing to attribute this sign to the Romans: Senatus Populusque Romanus...)

Location: Garratt Lane / Picture taken on: 04/03/2008