I liked the look of Jim's Spacers, so I made a set myself. I turned them on a lathe from a lump of ally I had in my stores. I had to buy the bolts ($6.50 Au each

) and had to file the heads down, as the Triumph bolts are a smaller head to fit inside the bar clamp.
The reason the bolts are so dear is because
a) they're high tensile
b) they're a fine metric thread, not commonly used, mainly automotive.
Haven't ridden with the risers on yet, but I'm hoping they might reduce the ache I'm getting across my shoulders.