Wow, I am not worthy. Major thanks for the input guys. Yes the insulation on the old alternator has flaked off a little, either due to age or overload. Bearings are dry as a camels ear lobe also, this would sugest it was passed it's best, and my tunes were the final nail so to speak. I have no mains electric in my garage, so have to run batteries and an inverter, I am a mechanic in a tool hire shop and through scrounging have put together a small honda engine, running a 45amp Lucas [old mini style] alternator and an ammmeter. If I have this running to charge the batteries and put a heavier load on it the amps can go beond 60+, hence my trepidation with the car. I did retrofit the ammeter to the car lastnite and switch everything on, lo and behold the amps went up to 50, and the stereo wasn't quite up to 11 [spinal tap]. I definatley think that I should be either investing time and money on a bigger unit, or just leave out the tunes till it's light and I can switch off the headlights. Shame because the theory sounds workable, something to limit the flow to 55amps regardless of the call of the battery. Engines and electrics I am ok with, but electronics come up a bit short.
In mechanical terms it is like resticting a pipe with a choke to limit the flow, as per my earlier question would an ammeter shunt do that?. Or would the call just cause it to get hot and blow?. Sorry for seeming a bit clueless. Yes you are right, I am ex motor trade, we just used to change them as a unit, service exchange. But none of the motorfactors round us do service exchange. They just want to sell you a new one, for £80+.
If it wasn't just coinsidence that the old alternator was on it's way out, it could get an expensive hobby.
Thanks guys, you've given me alot to think about.