Hi I also have 2004 +4, built at the same time as yours.
I spent quite some time working with the MMC & bush material. The main problems we found with the blue DEVOL bushes, which are nylon 66 not high molecular weight polyethylene.
being nylon the do absorb water so swell when wet, causing the steering & suspension to stiffen. the 2nd problem was with the design of the bush having a lip machined top & bottom creating a chamber that trapped grit etc and created a grinding paste that wore away the kingpin.
We developed a tested an alternative using Acetel filled with PTFE & silicone lubricants. this has been very successful on my car & also on a Morgan used for MCC trials.
MMC however decided to return to using Bronze bushes.
