All About Pocket Knives

Came across this knife my mother brought back from England over 50 yrs ago as a gift for me. It is stamped Arnold & Son on two of the blades and Sheffield on the third. Can anyone give me any more info on it? Also need some suggestions on cleaning and restoring it as it looks a little rough after being lost in an old chest for at least 40 years.

I would say that Arnold is a retailer and the knife was made in Sheffield hence the two stamps . If I were you I would try to find a London based retailer or cutler. The age is difficult but turn of the 20th century give or take 20 years.
As to cleaning I would just use an oily rag on the blade and may be beeswax on the scales.

HERE YOU GO ITS A START https://archive.org/details/catalogueofsurgi00arno