air hose

Is there a source were i can buy an air hose that connects to the manifold (part 5) below: also whilst replacing the alternator and rocker cover gasket  i have attached the earth cable but found another earth that is connected to the fire wall beneath the bonnet any ideas were this goes i have temporarily attached it to the rocker cover also. Thanks

That is a engine pre-heater hose and you can buy that at most auto parts store as they regularly go out.  

All you need is the diameter of the port then go buy some.

Think its the same as used aircooled Beetles;

https://www.ebay.co.uk/itm/185078470645?itmmeta=01HTVM3F1TJ4HX4Y6J3J1KKSE6&hash=item2b178957f5:g:UhYAAOSwadNhpl6M&itmprp=enc%3AAQAJAAAA0AfiExBOTdKePf%2BGabBx0tB1LKHBHgKV8c%2FJppqkBG6JsGPkyWJVgqDa4yA2sbRywC0PUzrq5xKu2LtcvKs05uHl%2BbSQvi4ouOO6M4liiJcqh8sA%2Bq5fWLRNHuIjDxpOC3i9vdgdQSCM%2B5icoEGKCiu0hKmCp71933RSijcNmTXR3ldMXA49TM7uFc7Q%2FRWa7T4vkRbkz9FyBDiR7NxQNtT0hzWdZ34TBjPlBZGI0qcHppq4dizIm4jZCXy3Yv9Pcc3k3s5AxXlE%2FVgifY7rPWs%3D%7Ctkp%3ABk9SR4TxjfTWYw

Thank you for the replies ani ideas where this earth goes i already have one on the rocker cover?. Thanks

Not near car at moment but I'm sure that goes to cam cover corner stud/bolt?

Thanks wasn't sure as there is another earth on the other side of the rocker cover but i have attached the earth in the picture to the rear right corner stud.