Right. I've taken some photos of the 3 spoke wheels I've got.

The first one looks like this :



The second one has slightly different stitching on the 2 side spokes :



The third one is slightly different again (joint at the top) :



Onto bosses; the 3 door Sierras should have the boss on the lower left, but most people will fit the MK3 or MK4 Escort bosses. The MK3 Escort boss, lower right, is the RS boss, the boss in the middle is the Motorsport boss. The RS boss doesn't, as standard, have the cutout for the indicator cancellor, as shown on the middle Motorsport boss, but most people just use a dremel or file to create it.