Thanks everyone for your comments. The fiddle is obviously very old - in black wooden case lined with tattered blue velvet and sporting ancient looking metal handle and clasps. The fiddle is a very tight fit in shaped interior. My guess is it's probably around 100 years old - the only mark I can see inside is "MEDIO-FINO".

The 'bowed bow' has a mother of pearl inlay "frog" and looks at first sight to be almost the right shape - until you increase the tension and then it goes straight. As suggested I think it must be warped.