7AFE air intake back to stock, Taking a 7AFE with cone filter back to stock Options

[dlinacre]

Hi. I'm planning to take my ST back to the stock air box and filter set up. It came to me with a half-hearted attempt to install a cone air filter already done. I've sourced the stock air box and flexible pipes. The stock box has 2 holes in the bottom part. One of these I think connects to a duct within the wing (I think this is a chamber rather than a fresh air source). The other hole I assume is for fresh air. Unfortunately whatever pipe or duct that used to connect to that hole must have been removed. Can anyone tell me where that pipe or duct should route to? Is it possible to fabricate a suitable part fairly easily? Or would I be better advise to try an source a part from a scrap yard? Many thanks for your help.