It's not an OK.
The mast is stayed.
The aft deck has a slot for the rudder to be lowered through.
Try the CVDRA classic and vintage dinghy racing ass'n, or possibly post on
http://www.yachtsandyachting.com/forum/forum_topics.asp?FID=8&title=dinghy-development
But I think there is something 'continental' about the shape of it?
That slot in the aft deck flummoxes me, but looking again I see rigging wires on the mast. The spray deflector on foredeck is reminiscent of a GP14 or Seafly, (but the hull shape is wrong for Seafly)., maybe even scorpion, but the\at slotted aft deck is an unknown to me. Maybe a foreigner or A one-off.
Tthat hull shape still reminds me of the OK I sailed , maybe somebody put a stayed rig on an OK hull and did something weird with that slot thingy.
Definitely not a Contender, OK or British Moth, very wrong shape for any of these. I'm not too familiar with old Snipes but that's where I would look. The slot in the aft deck shows that the rudder fits like a Drascombe from the top and I haven't seen that on a dinghy before. I'd also look at a Plymouth dolphin, they had a Snipe like hull.
My first glance suggests a Streaker, a ply single hander.
But now think more like a Snipe but the aft deck slot may be a modification.