Stopped by the local JD dealer yesterday. The special edition seat sells for $440 (list price?). There is also a kit ($110) that is used if installing the seat on a non-special edition tractor. Don't know if this is necessary or not.
The dealer had a 2210 on the lot. I didn't write it down, but I think the seat rails on the 2210 are about 6.5 inches center to center. Definitely less than the 4110. The mounting area on the 2210 is also a lot more open and flat than on the 4110.
I have attached a picture of the seat mounting area of the 4110. The seat is in its forward-most position, and the bottom of the picture is towards the rear of the tractor.
Unlike the 2210, the 4110 bottom rails are bolted into shallow C channels that are welded onto the bracket that is bolted to the tractor itself. The right end of the tape is hooked over the outside edge of a bottom seat rail. At about 8.5 inches on the tape, on the bottom side, you can see about half of one of the bolt heads of a bolt used to mount the bottom seat rail to the bracket. There are four such bolts, one at each end of the two seat rails. The C channel is about 2.75 inches wide and 3/8 inches deep. One of the edges is at the two inch mark. Two of the bolts that hold the mounting bracket to the tractor are just below the tape at three and six inches. The two front bolts are on legs that go down a few inches near the front of the seat area. Also note near the upper right corner of the picture that the seat belt attaches to the frame of the seat rather than to the tractor.
The bad thing is that there is a "black box" that sits between the C channels. The top of it is higher than the rear part of the mounting bracket, which is why the C channels are raised about an inch.
I think what would have to be done is to make up a couple of adapters that span the C channels and bolt in where the bottom seat rails do. Also, the adapters would need spacers on each end to make up for the depth of the C channel. The adapters would be drilled to accept bolts for the new seat rails which would hopefully fall between the C channels. However, my guess is that the new seat rails are wide enough such that they will land partially on the C channels which will make it difficult to bolt things together.
RRacer...can you post a similar picture or two of the underside of your special edition seat on your 2210 that shows how it all bolts together? What's the center-to-center distance on the seat rails? Also, it looks like the seat sits pretty high (10 inches from top of cushion to bottom of rails?) when unoccupied. How much does it drop when you sit in it?
Thanks,
Ira