Many thanks for replies.
I found a wire off the volume control but resoldered it and now it works fine. Needs new strings so will fit these as soon as I can get some. Will post photos as soon as I can get to take some.
I have just rescued an old Resonet Arco from my attic that I have had for about 15 years but have never played it. Is it worth restoring or should I just list it on Ebay ?