grammar - Syntax of this sentence

From Line 11: https://www.docdroid.net/847v2dg/img-20170413-0001-new.pdf.html

地図Bは南北を上下ではなく、左右に置いて、作ったものである。

I understand the sentence as follows: "Concerning map B, it is the card he made north and south not being top and bottom and put it left and right."

My main issue so far is that 上下ではなく has no connector to it like て form. The fact that 左右に置いて is て form doesn't make things easier. I could imagine that 南北を上下ではなく...作った form one attribute for もの. 左右に置いて could be, well, another addition, an adverbial phrase maybe, I struggle determining the syntactical function. "He made north and south not being top and bottom and put it left and right" I also have problems with the semantics of て form in this context. simply chaining it kind of still works, but I feel like it should have an adversative meaning: "He made north and south not being top and bottom, but put it left and right." But I haven't learned so far that て form would be allowed to use this meaning.

Answer

Your instinct is not wrong. ではなく is equivalent to ではなくて . This is a general rule: the く form of an い adjective (and in this case, as in most cases, ない and たい forms of verbs are treated as い adjectives) is used (more often in written than in spoken Japanese) as equivalent to the て form. The pattern A ではなはく[て]、 B , "not A but B", can often be rendered "B rather than A".

The sentence goes like this:

地図 B は Map B

作ったものである is something that [unspecified subject] made

置いて placing

南北を North and South

上下ではなく、左右に not [at] top and bottom [but] to left and right

Since the subject is unspecified, I would use an English passive when translating. Thus:

Map B has been drawn with North and South to left and right rather than at top and bottom.

Hint: don't be misled by the punctuation mark 、 . It doesn't always (or even often, I'd say) mark off a grammatically distinct section of a sentence.