Because the Adaptamatics were discontinued before the advent of the K mount, you're out of luck finding a K adaptamatic mount. But you can use an M42 to K adapter, which will allow you to use your adaptamatic 200mm on your K-mount Pentaxes.
Conversely, you can upgrade to the Tamron adaptall-2 200mm f/3.5, which is probably at least as good as the one you have now. And you can use an adaptall-2 K-mount adapter with it. Here's one being sold by KEH on eBay:
http://www.ebay.com/itm/Tamron-200m...803202?hash=item43ea6cbb42:g:33EAAOSwuAVW0vZC
Conversely, you can upgrade to the Tamron adaptall-2 200mm f/3.5, which is probably at least as good as the one you have now. And you can use an adaptall-2 K-mount adapter with it. Here's one being sold by KEH on eBay:
http://www.ebay.com/itm/Tamron-200m...803202?hash=item43ea6cbb42:g:33EAAOSwuAVW0vZC

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