Think it may be a bit far for you Andy ( Essex ?)
Suspension drama roles on,
Went and looked myself today and see the issues.
The original shock looks to be a 10mm Ish shaft and nut!
The new shaft is approx 15mm
The kit they sent at the second attempt is the right stuff but wrong sizes as all to small, it's not big enough to go other the shaft above!
So,basically the sleeve would need to fit within the oem mount but would need to be big enough to go over the 15mm shaft. The obviously the washers would need to have a 15mm plus hole and the nuts be the appropriate size.
Bc racing are a bit Jekyll and Hyde and go from being narky to nice. They are still telling me the kit is right for an e92 and an e93 m3, but to me that's impossible as the oem shaft is much smaller than that provided, ergo it would never fit with oem parts! The 15mm shaft won't physically fit through the current oem top mount.
They have emailed the manufacturers and are trying to resolve the issue?