The smoke is as a result of engine oil getting into the combustion space above the pistons.
It can come UP past the rings, or down the valve guides or in the inlet manifold.
Does your engine have valve guide oil seals on the guides?
Some engine should have them. Others don't. If it should have them, they may be done.
Even with a good compression test, if the oil scraper rings are U/S , they will not draw the oil off the bores, and too much oil will get up to make the smoke.
You can check the valve guides quite easily - get the 1 - 4 pistons to top dead centre, take off the rocker shaft, take off the valve collets collar and springs, and waggle the valve stems to see how slack they are.
Put it all back together again. Don't bother with the 2 - 3 cylinders. If 1 & 4 are ok so too will be 2&3.
MY suspicion is rings BUT ........ IF YOUR ENGINE BREATHER is knackered that could cause it, and that is VERY EASY and VERY CHEAP to fix, so see to it first!
CharlesY