I'm not an engineer, but it looks like Magellan Aerospace Kitchener (ON, Canada) built Wing Components and Spirit Aerosystems (Wichita, Kansas, USA) built Wing Spars and the Front Fuselage. Could have been either one of those.
My guess is it's Spirit as it's mentioned in the notes they build 75% of the airframe in total.
I was surprised to find that a lot of information is found online. However, there's no specific mention of "pickle fork" here: http://www.airframer.com/aircraft_detail.html?model=B737#Air...
I'm not an engineer, but it looks like Magellan Aerospace Kitchener (ON, Canada) built Wing Components and Spirit Aerosystems (Wichita, Kansas, USA) built Wing Spars and the Front Fuselage. Could have been either one of those.
My guess is it's Spirit as it's mentioned in the notes they build 75% of the airframe in total.