Earlier this year I sold a quantity of mixed silver and gold that I had been stacking for a period of approximately 20 years. The most recent purchase was in 2013. Due to the length of time that I have been stacking, I don't have access to all of the receipts (Most were lost when a shed flooded). As a result, I can't remember how much I paid for the metals.
I am an Australia resident for tax purposes.
I also have a pre-existing capital loss that has been rolling over for several years.
Do I need to claim CGT? If so, can I claim it against my existing capital loss?
How do I calculate it when I don't know exactly how much I have spent on the metal over the years?