Byzantium is stoopid (and broke) and England can trade Iron Working/85 gold.
Iron Working reveals Iron Ore, which is found on Hills and Mountains. Within four tiles of our current borders are 3 Mountains and 9 visible Hill tiles. Two of the nine Hills have Incense, leaving Seven of Nine (go Jeri Ryan!) as possible Iron deposits. That doesn't sound too good for us having a native source of this precious ore.
England wants Writing and Warrior Code for Iron Working, but we can counter offer just Writing for IW and 39 of 85 gold and they will take it.
The bigger question is do we want it.
Iron Working also unlocks our UU, the Gallic Sword, which hits like a Sword, defends like a Sword but moves like a Horse. So, we win a battle with this bad boy and we kick off our Golden Age.
We must know Iron Working before we can begin Construction, which allow aqueducts and colosseums. The first we need, the second we don't. Construction is generally one of the last techs learned in the Ancient Age; either that or Currency.
Once we learn IW and Iron is connected (which could happen if City 3 is sitting on an Iron Hill) we can no longer build Warriors, which are nice and cheap and can serve as MPs untile we get into Repbulic.
Trade Assessment
No on an Iron Working trade in the near future.
We are far away from England. We both have 3 cities (London, York and a third city West of York across the lake) but we will soon have more. And we can manage them better than Elizabeth can. We have little to fear from them.
We could accidently trigger our Golden Age. We don't want to do that in Despotism with only a handful of cities. Once we have seven cities or so, I think we should begin to make plans to start our Golden Age. I do think we should wait until we are in Republic before we have our Golden Age. I think we should have at least 10 cities or maybe even have gotten the Forbidden Palace popup before we trigger those exceptional twenty turns. But the Golden Age is a public decision and my views here are focused on not abusing that one time gift.
I am very concerned about triggering a Despotic Golden Age. Perhaps too concerned; I cannot tell.
We do not have a likely source of Iron inside our borders.
We could meet other people and get it cheaper. Cheaper doesn't mean less dangerous to our interests; just cheaper to buy. We might even make some cash by selling it to someone rich but stoopid.
Given that England is our Mortal Enemy, trade might be considered out of the question. That is a decision for our citizens to make.
Random Musing
If we wanted to start our Golden Age with the destruction of England, whether soon or in the distant future, we could keep some Gallic Swords garrisoned in our cities until the time was right. Depends on what we plan to do with the High and Mighty Limeys.
If you're getting your info from the Historical Statistics Department thread, you'll need to go to the last post, always. The current info will ALWAYS be in the last post. The last year of the last Game Session was/is 1830BC. 
