http://zoerk.com/
if you want precision in custom made adapters for a resonable price
Zörkendörfer is the guy to make it for you. He is a genius.
A N to K adapter for close up will be an easy thing for him.
He will sure have a qualified opinion.
When I talked to him already years ago, he (Mr Zoerkendoerfer) told me, that he no longer does that ;-)
I have quite mixed feelings about his stuff, when one of his famous solutions fell apart....
I'd rather talk to the MD of Novoflex, whom I know, they make the best adapters and also make custom made ones!