Odd Livonia Solidus?

I picked up what looks to be a Livonia Solidus recently (image below) due to how far off-center it was - interesting to see the marks on the plate around where the coin should have been cut from. I tried to attribute it using the Standard Catalog of World Coins (I have the 4th ed of the 1600-1701 volume), but am having difficulty.

It looks to be KM #50 under Livonia - it seems to be the right style, it looks to have an IG (as in RIGA) before the date, etc. - but that particular type is supposed to have ended in 1660, while mine is 1662. Also, that type should be in silver, while mine looks to be copper - arguably billon, but a very very low amount of silver, then.

What is this? Is it just an error in KM and the type does run to 1662, although 1662 is listed with a different style under KM #55? Is this a contemporary counterfeit, as is noted for certain dates of KM #55? Or, is this just listed elsewhere in SCWC and I haven't come across it yet? I did try Sweden, Poland, etc. as likely candidates.

Thanks!