GDay fellas, well, I have given up hope... this is from century arms in Aust;

Re .470 we are upgrading website a db .470 Manton, plain rifle top lever with hammers for US$7000,00 .will be offered. The calibre you want is the most wanted of all db rifles, a good hammerless is worth around US$20,000.00 for an ordinary up to double that for a very nice top English used rifle
CenturyArms.

I am going to stick with my bolt .458 for a few years yet!