Andrew, Yep Model 06487. See following link here at BUDs----------budsgunshop.com/product_info.php/products_id/52117 />You can search the make and model and see where it is available.

Andrew, Buds has what you need here Sir : budsgunshop.com/product_info.php/products_id/52117

Oops buds.link here
budsgunshop.com/product_info.php/products_id/52117

There is one listed on buds but its currently out of stock, hit the notify me when available button to recieve an email when it comes back in.
Available for back order here
https://anthonysfirearmwarehouse.com/store/drake-southpaw-20ga-28-lh-5-choke-tubes-269498/
Or you can look on sites like Armslist.com or auction sites like (G)un Br0ker