Does the "smoke" hang around in the air or just sort of dissipate straight away, condensation of the hot moisture in the exhaust just disappears usually.
I'm loathe to mention that the float levels could be a millimetre or two lower going by the tube thing, 14.5 might suit better. (don't do it unless it winds up that it is a little rich and you can't adjust around it) ask Desert about the difference it made to his, he mentioned changing his to 14.5. (also stops slow weeping around the bowl gaskets if they're always just above the fuel level, unless it's on the sidestand.)
At least now you know setting the floats by measurement will be good enough to get a consistent level in all the bowls.
It's got new stem seals, plus it's a fairly low mileage engine, guides shouldn't be gone yet, (and the head guy checked them too) new seals would cover even worn guides for a while.
Keep an eye on the head to cylinder join for leaks if you're worried about the head gasket, but both of those surfaces were machined true, and with HD studs.
You can change the oil if you want, a little bit of old oil in the tank plus any carbon deposits in the cases will turn it all black pretty quick, doesn't necessarily mean it's no good.
Just curious, what oil did you end up using?
See what I meant about differing break in opinions, some hard, some gentle, I have always heard that big diesels idling for hours without load will polish the bores until they wont hold oil on the bore surface properly. (shouldn't have told you that, you'll be thinking you've done that now. You haven't, it takes longer than ten minutes. 15 at least.)
It's too early to worry just yet, give it a few miles and see how it settles.