Head gasket gone? Skim the head? Aaargh..

Hi I'm new to this forum..not too new to mechanicing luckily..have a T reg freelander with a 2 litre diesel engine..Had a small water leak a couple of weeks ago, I bunged some jollop in the rad and it went away, stupidly I carried on ( I had a manic couple of weeks ahead so didnt have time) A few miles down the road, with a caravan on the back the temp guage rocketed-i pulled over pronto..refilled the watar and limped to the place I was heading..there was a big split in the water pipe in front of the engine, I bodged it and a refilled the water..this got me to the next gig, but on the way home from there the temp guage rocketed again, the engine was totally dry, had blown apart my bodge and was very hot..sizzling!..I left it awhile to cool down then limped home, stopping every time the guage shot up and topping up the water...
So...now it will run for a while then over heat..the water will blast out if I open the cap when its hot,but then all drains away so the header tank is empty..I refill it and it again lasts ten miles or more, then overheats and I go thru the same again.
I'm loath to dismantle it, but guess its the head gasket..although as far as I can tell theres no water in the oil,oil in the water, or steam in the exhaust! but the where the heck is all the water going??
Anyway..tips on the head gasket change really needed..do I need to skim the head?? do I need to dismantle before i know what thickness of gasket to order? Will I need a whole top end gasket set? Will I need new head bolts??
This far the car has been very reliable with a FSH showing very little has needed doing...please help me get her back on the road!!
Thanx!!

Been scouring t'internet and heard that the expansion tank filler cap will sometimes cause this sort of behaviour..there is obviously water coming out of here when the pressure is high..there are stains all around it but I thought that was due to excess pressure pushing the water out..also there does seem to be bubbles in the stream of water coming back from the top of the rad, any ideas??

Had it been a 1.8 petrol I would have said burn it!
As it's a diesel and a model not really renowned for head gasket failure I would say firstly do the cheap fix and do the filler cap as you've read about. If that doesn't fix it I would be inclined to look at the water pump or thermostat next. Head gasket failure you would notice a loss of power due to compression loss so if this is fine you may be ok on that one. Good luck.

Speaking to a friend who works for a LR main dealer it would appear that the L series can suffer from head failures (cracking), no personal experience myself but may be worth asking your LR dealer or local engine repair specialist.