Nicely written Trev.
There are a lot of good one piece bushes on the market.. heck theres a lot of people putting many miles on them. Just depends who did the machining and who made the bush.
I think this is where companies like SRM
(in the UK and others around the world) do good. I don't like everything they do, but I do like most things and wouldn't considering going anywhere else for the "same part" The bush I have recently had fitted is one of their PB ones.