Help please.... Before i burn it.

[anto]

I still think the pump is probably rammed full of rust/ residue and general shit tbh

Could well be to be honest, guy i bought it off had it full of diesel though..
it wont eventually clear itself if driven will it?...

When you blip the throttle does it rev up like its responsive or is it very slow and numb? So to speak. Do you have a hand primer?

slow and numb id say, no power to it at all like

This is what i found when i opened a pump after it ran like you are describing;
I wouldnt say itl clear itself.