Aux fuel tank for 123, where can I find one?

[Ironforger]

Hello,

I understand that dealer installed aux fuel tanks for the 123 diesels were rather comon in the 80's. 20 gallon tank mounted in the trunk against the back seat, below the speaker deck. Anyone know if these tanks are still avail new? or new old stock? Apparently the dealer purchased them as an aftermarket product.

Setting up a WVO 300D. A tank like this would be optimum.

Thanks