The poly bushes are worth the time and expense. No extra firmness at all, but significantly sharper handling in every respect.

I can second that and I’d also recommend adjustable dampers

The top wishbones have always been a must in poly, before poly we used to use Nylon bushes

Did you find much difference in the sound after this?

I felt it was a little quieter but still a good sound and no drone

Ok, going to have to look into this as I'm getting a bit fed up of the sound at 70mph, previously the engine was fairly quiet (it's doing sub 3000rpm) but now I get out at the end of a journey with ringing ears. It's the boominess of the exhaust at exactly this rpm which is the problem, as it's quiet at both 60 and 80mph.

I think one of the issues is the back box mounting is not up to the job as its just a tiny strap and has already started to fall apart. I'm going to replace that with a proper rubber isolator.

Next up I'm suspecting the replacement engine mounts I put on. Despite them being "standard" mounts from brookhouse the rubber appears to be rock solid with no give. I'm considering drilling a few holes in these to try loosening them up.

Last resort will be to add another mid silencer. Rustinmotion did you find there was enough space under there given the centre pipe is already extremely close to the floor? Also did it help much with the bass / boomy frequencies?

Basically the silencer and straight pipe match the length of the fat long silencer that comes with the Simons kit, the new silencer starts at the hanger position and fits where the floor plan steps up for the rear seats

Hmm, strange problem noticed this week. The rear half shafts now have a quite large amount of axial play, I'd estimate between 5-10mm. I originally noticed this as a large amount of lash in taking up drive, there is a noticeable thunk when taking off or when changing down.

Given that the nearside is shimmed (and it was correct when I rebuilt the axle, negligible movement) is there something that could cause this amount of play to open up?

False alarm on the axle play, I measured it at less than 0.5mm, it just sounded significantly worse when yanking on the wheel. I think it's possible it should be even less than that but it's close enough, I reckon it's better to have a little extra than have the bearing too tight.

Oil seal is completely shot on the nearside though, big puddle under the wheel and brake shoes are contaminated, so seals, gaskets and shoes are on order.

For what it's worth I used a £14 US PRO front hub puller to get the drums off and it worked absolutely fine.

Most US Pro tools are pretty good to be honest, i've got a fair few of them and so far, not been let down by any.