Anyone who trusts bankers and insurance companies can't have been living in the UK for the past 10 years. We have mortgage protection mis-selling, endowment,life assurance, pensions mis-selling. The whole shebang. Insurance companies will try every trick in the book to avoid paying out. I would not rely on a casual throwaway comment such as "one or two carcases" etc. If there was a limit say £5000 in gross revenue from selling carcases then that last of the season carcass would be sold at whatever price was necessary to keep below the limit. Moreover, it is the stalking and shooting activity which is the greater insured risk, so if a catastrophe happened during the shooting, necessitating a claim, the last thing on my mind would be selling the carcase.
I have a lot of time for David and the advice given on here but this particular reference to insurance cover is surely beyond his remit, and when you are in court suing the insurance company for a pay out, having been abandoned by the BASC, David's comment is not going to help in any way. My suggestion would be for the insurance company to write in black and white the financial limit placed on "recreational stalking". Otherwise buy proper cover elsewhere. You need certainty in what you are paying for.
Get a written statement from BASC on what the limit is otherwise assume you are not insured...