Just a word of warning, I tried to get some spare parts for my 2008 slayer last summer, and evans had to order them in from Canada. It took about 2 months to get the parts that I needed. I think silverfish still have some old spare parts, so it might be worth calling them as well.
What year frame does your mate have? I only ask as I snapped mine, and it could be used for spare parts.
My mate’s slayer is an ’08 model I think. Don’t know if he’s been to our lbs where he bought it, but they stopped selling RM a couple of years ago. He’s at work just now, but I’ll let him know about the generous offers. Might work out quicker than ordering from Canada.