It is hard to say whether it would be close to your friend's salo or not. Some but not salo is smoked; it is often dry cured but not always; some is aged but not all. Differences in approach change the results a bit so I can't really answer this, but you could try a few ways and see.
I don't think I have ever had brine-cured lardo (I've laways had dry-cured and that is the type I've made).
Use skin-on fatback. If at all possible don't buy commercial pork. Find heritage. So much better for something like this.
Bacon is not typically cold smoked. It is hot smoked but at the low end of the hot smoke range first, then temps are raised a bit, then a bit more. Yes, you would keep the finish internal ~145/150.