I would like to add something for those wanting to use silver spokes (hope you don't mind Sideshowbob :wink: ) I managed to fit silver spokes to my M wheel as is, others haven't had the same luck. With the in mind I recently did a little cut a shut job on my old, spare, bottom spoke using my little Dremel type tool. I didn't have the steering wheel available to offer it up to (and wasn't going to dismantle mine), so that's my excuse for the less than perfect finish. Hopefully it will offer a guide to others wanting to do the same. Have z4alfie to thank for the photos and being a guinea pig!
First thing I did, as it was my first time cutting this plastic, was to practice on a part I knew I wouldn't need.
This shows the cut and original spoke side by side.

Some points to note here:
1. On the original spoke, right, there is a small clip at the bottom of the central cutout. I believe this interferes with the thicker wheel, so removed it.
2. Where you can see white plastic in the spoke on the left, I used a sanding tool to cut back the plastic as much as possible, to allow more room around the spoke.
3. I cut the spoke a little below centre cutout, but you can see that better from the other side.
4. The initial cut left sharp corners. These were sanded from underneath to avoid damaging the surface on the top.
This shot shows how far down I made the, ahem, horizontal cut. (it looked perfectly square at the time

)
Another from the side to show the different profile, while it isn't shown that clearly I did trim back the folder edge on the bottom:
Here a picture of the spoke on the wheel which z4alfie said went on without any drama, so I assume the cut is in the right place. I think a key point here was removing that clip from the underside.

It isn't as straight / square as I would have liked, but if I'd had the wheel to hand it would have been tested and tweaked. Honest.
Here's a picture I took post hatchet job. Shows the repair to the screw lug. These things have a habbit of snapping when removing the spoke from the original wheel.

As you can see from the base of the one on the right, they're a little flimsy. Just glueing it back on doesn't stand up to the rigours of trying to fit. This seems to have worked:
1. Using super glue the lug into place as the original.
2. Cut up three small triangular strips of plastic to match the profile of the spindly little uprights at the base of the lug - I used the offcuts from the main work as donor material.
3. Glue one of the small triangles to the side of the uprights and the third in between. They will stick out on all side, don't worry. Leave to set.
4. Using a Dremel (or similar) rotary cutting disk, trim down the plastic at the base of the lug so that there is nothing protruding.
Hopefully the picture illustrates exactly what I mean.
It goes without saying, if I can do something, it isn't that difficult! Give it a go.