sad to see you are still having problems, i know how you feel
To be honest it could be something really simple and a very quick fix, it takes very little oil on something hot to cause smoke, I had a weeping oil feed connection that caused a lot of smoke when a few drips went onto the turbo, it has to be put down to a rebuild/engine work settling down sometimes, it does not look like much damage was caused
I would get a fan shroud on there if I was you as that can be helping with the cooling, you said your gauges are not working, my Defi's have saved me a couple of times from overheating and one occasion poor fuel pressure due to a spilt line for example
Hope you get it sorted soon, where will you take it now ??