Many thanks for the replies!
You may well be right about that, although it can also be used as a parts washer I think. There is some sort of valve that closes the sieve drain when you close the lid, that made me think it is a parts washer (to prevent the volatile part of the liquid from evaporating), however the tank is very clean on the inside and can be locked so that makes it more likely that it has been used to store fresh oil
I also tried looking up the patent but no success. So late Victorian would mean pre-WW1 if I am not mistaken?
Thanks, I went looking in the very same street as well, I find it fascinating that a lot of manufacturers were located in small workshops. Sadly the remains of these places are disappearing at a fast rate.
That is absolutely true, it was a different world. I found this tank hidden in a collection when checking out a stationary steam engine. This engine comes out of a tannery that was demolished in the mid 70s to make way for Brussels airport. I ended up buying both items, the price/weight ratio of the tank being definitely higher than for the engineđ