Looking at the parts breakdown for the 4115 from JDParts,it sure looks as though it will work. Really isn't much different than my 2520. This is based on your 2520 having the "older style" rear linkage. It was changed on the late 2011-2012 models.
Wow. I cannot believe this is such a difficult question. Tried 3 dealers, no one knows the answer.
Called JD corporate, "we have no technical support line, our dealers are our technical support". Worthless.