Great reply MK, I'm sure that really helps.
Kevthom, I think those machines were once sold by screwfix, you could do worse than ringing them and see if by chance they have one or could point you in the direction of one.
What is it you need to know about it? I'd imagine it's a very simple machine regarding controls, on/off switch, switch/knob to control the welding voltage and a rotary control for the wire speed is probably about it.
sorry for the short reply I thought I had tipped in the rest before i sent but I got distracted. What I meant to say was the manuals for DIY welders are normally pages of don't do this e.g. use in rain and keep away from children followed by a wiring diagram and maybe a parts list as for how to weld the ones i have seen have been very poor. You would be better asking direct questions on here and we will help you out