SIck E30 327 engine

[Scoot1]

Bought a built up an E30, 327 engine (E525 auto bottom end 320 head with 325 cam) completely rebuilt, excl ancilliaries 9fans hoses fuel pump etc) off an E30 zoner!
Lots of receipts for the engine build, engine looked genuine and good.
The engine I was told was fully rebuilt but could not be seen/heard runnning.
I bought it for a considerable amount of money.
I had the engine put in my cabbriolet, along with brand new clutch, rad, hose kit, ECU etc etc. ran it in (below 3000 RPM for 1000 miles) which has taken me two summers (no winter use).
Took it for an MOT yesterday after being stood for the winter in my dry, warm garage.
The car overheated dumping water from expansion tank overflow, I took the thermostat out, ran the car to remove airlocks and water is bubbling/erupting from expansion tank (with cap off).
Also Blue smoke emitting from exhaust when revved, idle for a while and it clears but when held at a constant throtle I can definitely smell oil burning. I am very concerned by this and would welcome any advice, no smart a#rsed comments please re should have bought this and not been trusting it does not help ta. I thinking is it the head gasket, cylinder head? I am trying to get it stable enough to analyse the gassess in the header tank. Advice please...

[Scoot1]

OOPS thought the post was relevant to said forums given technical nature of question, but can appreciate the rationale associated with your comments.

Will follow up on your thoughts, but I think the vehicle being parked for seven months has not helped, following a complete engine rebuild. Another consideration is the blue haze due to cylinder bores being glazed prior to rebuild causing oil to slip past the new rings causing smoking.
Have pressure filled cooling system, this has done the trick no more eruptions from the expansion tank, will check gasses though to be on safe side.

Cheers Will

[Scoot1]

Thanks Will, checked oil and no emulsification has taken place.