Upgrade to 420R

Friday, Aug 07, 2026 · 557 words · approx 2 mins to read

I mentioned in the post about the car starting life as a 360R that I was working on figuring out who upgraded the car to 420R specification with the help of Martin Phipps, the archivist at Caterham back at the factory.

Martin has been incredibly helpful in my journey to uncover the timeline of the car before I acquired it, so that I can properly document its entire history as much as possible. The owner prior to me bought the car in 420R spec from Oakmere Motor Group and the strong hint from Martin was that Oakmere likely undertook the upgrade work. The problem was figuring out how to have that confirmed either way.

I’d been in touch with Oakmere a while back because Simon Hoade spotted that the number plates on the car had their name on them, but calling and emailing their generic sales mailbox bore no fruit.

A few weeks ago when working with him to get the original order sheet and early factory information on the car, Martin was then kind enough to use his contacts at the factory to find the right person at Oakmere to ask directly, rather than hit their generic mailbox, and I ended up with a very swift and positive answer.

Oakmere’s head of aftersales confirmed that they upgraded the car to 420R specification in late 2018 before preparing it for sale in early 2019. My seller agreed to buy the car in February and Oakmere undertook further work in early March to prepare it for my seller by servicing it, fitting the Aces shift light system and repainting it from its original Gulf Blue and orange to the current green and orange colour scheme.

Oakmere switched to a new computer system at some point in the early 2020s and so I don’t have access to their original paperwork filed away for what they did, but at least Oakmere were good enough to confirm the work done and the exact dates.

The most important thing was working out whether Oakmere upgraded the car or whether that was done before they took the car on to sell. Now I can put together a reasonably comprehensive timeline of the car’s life to this point and then keep going with my own changes and milestones.

Update: I’ve put together that rolling timeline which I’ll keep updating.

As is common for me recently, I need to thank Martin and Simon for their help in navigating the problem space and for working out the best way to help me get to the bottom of things with Oakmere.

Lastly, big thanks to both of the gents at Oakmere who worked with Martin and I to dig out what I was looking for, and to my seller for passing on key information about the car during his ownership.