Well this might be a snip for someone at £99.99 buy it now, ships world-wide.
Item is located in Lodz, Poland.
It has the look of a 1970's guitar and I would think it is a conversion rather than fretless direct from the factory. The Japanese made many guitars like this that would be sold under various names in European countries, which may be why there is no brand name on the guitar.
Take a careful look at the pictures (all 12 of them) especially the bridge, you may be able to date it better than me.
The Guyatone factory was active in Japan in the 1970's onwards.
The seller says "special black strings" but to me they just look like badly corroded strings.