Just an update, the spec and description as follows from the seller.
This bike is a custom build and design, from completely new parts, starting with a Planet X RT58 alloy frame with carbon forks and using Shimano 105 components with some Tiagra parts and upgraded wheels. The bike has only been ridden for testing purposes round the block and so is brand new - see photos
The RT-58, designed and built by Planet X in Sheffield is an alloy frame with carbon fork and tapered headtube, built for all day long comfort. It is ideally suited to riders looking for a fast yet comfortable all-year road bike. Constructed from 6061 T6 heat treated alloy, the build is strong though anything but conventional: its chunky downtube and tapered headtube provide stability and the cross inspired flattened top tube adding extra strength, it lends itself to sportive style rides; long days in the saddle, eating up the miles.
The bike is size Medium (54 cm) with a standover height of 78cm. The effective top tube (horizontal) is 54.3 cm. It is probably ideal for rider height 5’9 to 6’0. The overall weight of the bike is 9kg.
My husband and I are passionate about bikes - he was a keen cyclist but has been ill for several years and since then we have been custom building bikes from scratch after carefully choosing quality components. We don't make a profit (often its a small loss) but we do it because we love it and it keeps us involved with cycling.
Seems pretty genuine?