Hi James, thanks for your comments. We are still learning, so will take all advice gratefully.
Pic One, We didn't self tap it, so I'm pretty sure it's okay. I didn't actually do it myself though, so will make sure.
Pic 2, No, we didn't mask it, but did clean the wet paint off that part before it dried. We also put some copper grease on both sides of the shim before we put it all back together, to ensure it didn't rust.
Pic 3. I'm not sure. I'm pretty sure they just locate off the studs? I've never heard of Hubcentric spacers.
When you getting to Snett? We are testing in the afternoon.
Cheers