engine rebuild specialist recommendation

[gertrude]

Hi there can anyone recommend someone to refresh my engine it was originally from JH Aircooled Wolverhampton but i understand they have gone out of business and i am looking at getting the engine rebuilt to a high standard as was done before as I use this bus as a daily traveller and we use it for holidays and touring europe so needs to be realiable thanks I am in Northamptonshire so anyone in the Midlands would be fantastic thanks