I Think.. that it's German, about 100 years old. The Neck looks like a Dovetail joint but these pics are really not the best to see the actual Bass and wood grain. Look at
MY webpages of Basses and get me some shots like that. Take the kind of pics YOU would want to see when shopping for a Bass. It's the same idea.
England imported instruments from Germany for the low end and with that stained fingerboard I believe that's a good sign. Also, with the nicer Rib linings I think is North Germany but never was this kind of Bass made in France.
The 3-string is a mystery because those plates look strange. Many 4-string Basses were converted to play as 3-string by some in England, France and Italy only to be put back as a 4-string later. It could have been made originally as a 3-string in German for export to England where 3-string was more standard then. I have seen other German Basses but lower end than this made as 3s. I suspect the same reason. This may be a nice Bass for German but was still cheaper then to import this than to make it I would venture to say.
Being that you are near New York, take the Bass to BOTH Arnold and Jeff so they can have a look on the inside. I don't think this is English with that Dovetail. The Gears on the matching 3 are 100% German from 80-140 years old or so. I am not positive on the age but certain on the Origin. The 4th gear might be a replacement from when it was put back to a 4-string. Finding this in London is a good sign it may have been used as a 3-string if not born that way.