Well today i decided to have a nose and make sure it wasn't something simple that i was overlooking causing the problem and i think i may possibly have found it. But would like somebody with much more mechanical knowledge before i go ahead and fix it.
Firstly i took out the sparkplug to make sure i was getting a spark, yep no problems there, turned the engine over without the spark plug and could see the piston was moving freely, so thats a good sign then i just looked over the rest of the engine and found this:


The inlet manifold is shot to pieces some of those cracks are hugely deep but i can't see properly if they have gone all the way through, would a hole in the inlet manifold stop the engine from firing? i would imagine it reduces compression and leans off the fuel air mix enough o stop the engine firing? but i don't have enough experience to know for sure.

There is still the problem of the seizure when i let the clutch out but that could just have been my perception being wrong i was going down a steep hill... very quickly the engine cutting out like it did could well have made it feel like it seized up, when i get the engine running i can know for sure and sort that out as a separate problem if it is one.