I would support using Millers as well.
They are just up the M40 outside the M25, not far from London at all and easy to reach.
They are independent of Morgan and so have no axe to grind.
They race Morgans and so know what to look for in the car and any possible damage due to racing as well.
They did mine before I purchased it (S2) and were very thorough and good value. I was very happy.
