I have a 1982 T25 with a water cooled 1900cc engine, i have just brought it and got it cheap as "it may need a head gasket". The guy who sold it to me hasn't had it looked at by a garage but was advised over the phone this was the most likely problem.
The van runs very well, starting nearly first time but after about 2 mins the oil buzzer comes on and stays on!! There dosent seem to be any loss of power, and i have driven it up some big hills on the way home over an hour long journey.
On the engine side there is oil in the coolant mixture and both oil and coolant levels require constant topping up. There dosent seem to be any water in the oil, and although the temp gauge is not working (red light flashes on ignition and that's it) i wouldn't say it was excessivly hot.
I have read that the oil cooler pump seals can also let oil into the coolant.
At this point i will say this is my first van and although im not idiot....ok im a bit of an idiot and i know nothing!
I would like to diagnose that it is definitely the head gasket before torching it for the insurance money... i mean finding a recon engine or repairing.

What is the best process to go through and are there cheap alternatives that can be covered first.
If it is the head gasket, is this the end of the world? How much does it cost?
Also i am based in Plymouth, Devon does anyone know of a good garage that i can use down this way.
Any help or direction would be greatly appreciated