Window lock help

[Martyn1984]

The handle and lock on my window has stopped working and will not turn. Have taken the window apart and am still unable to fix. Does anyone know what type of locking mechanism this is called and any ideas where I can get a new one?
Thanks!

 

[crank39]

What does that marking say just above the handle, if its Roto then its this one but its obsolete so you'll need to retro fit another system, you'll need the same backset, hole centres for the handle are all the same, take the much out to see if its inline or off set, my guess its inline

http://www.dgsupplyline.co.uk/windo...ceplate/roto-k123-single-track-espag-bar.html