the business called delisted.com.au provides a service (at a cost) for buying worthless shares so that capital losses can be crystallised. It is a reputable business.Here is their link re TGS shares https://www.delisted.com.au/company/tiger-resources-limited/It also provides info re companies no longer trading on ASX. I do not know if they will do CFD's for you or if you would find it worthwhile.