Limiting a delivery method

Hi all,

I've created a new delivery method (Special Delivery Postage) which I only want available online on one performance. At the moment, it's appearing on all productions with the Internet MOS. 

For some of our productions, we've used LTR_TNEW_DYN_SHIPPING_METHOD to limit certain productions to e-ticketing only. But, as this is for merchandise, we need the options for standard posting, and collection at box office, to still appear in the drop-down, along with the Special Delivery option.

As there a way to remove this new delivery method from all productions, and to then make it only available as an option on one?

Many thanks,

Hannah