Funleader started selling a separate DIY Helicoids for the Contax G45 f/2 lens to Leica M-mount conversion. The Helicoid will allow you to convert your own Contax G45 f/2 lens to a Leica M-mount version (the original G45 lens is available on eBay). The Helicoid conversion is much cheaper than the already converted lens ($539 vs. $1,199) – so, if you already have the original G45 lens and are looking for a DIY project, this one is for you:
Previous coverage of the Funleader Contax G45 f/2 to Leica M conversion lens can be found here:
Converted Contax G 45mm f/2 lens for Leica M-mount by Funleader
Just announced: new Funleader Contax G45 f/2 converted lens for Leica M-mount