I'd recommend finding a second one to convert this one and figure on a few hours or more to convert. Personnally you can do what you want, but I wouldn't do it.
Don't know about the 46W baler, but a few months ago my neighbor bought an IH 57W baler, lubed it and baled 8 acres (about 250 bales) without problem. He get it going using his Ford 8N, but had to borrow another neighbor's JD 2640 because the 8N in low gear moved too fast and overloaded the baler.
Don't know about converting to twine. I have a MF-124 two-twine baler and from what I see in the manuals I have, converting it to wire wouldn't be too difficult.