dead easy found a piece of exhaust pipe in the workshop which had the 57mm i/d for the silicone hose , the welded a large repair washer on the top and the hole in the washer just need drilling out to allow the tyre valve to pull through, even though the tyre valve was a tight fit i ran some sticko flex round the base of the valve to give it a good seal. once it had set i turned it up side down and filled it with water to test for leaks there was non job done . I did not bother fitting a valve guage as will be using a tyre inflator which has a guage on it