I'm not sure if this counts as "conversion" since I haven't modified the keyboard a single bit, but I use a similar terminal model M with RJ45 plug, connected through a trivial plug adapter to PS/2 port.
It's PS/2 compatible (yours should be too) and there are only three differences between this keyboard and a typical PC keyboard:
1. Different id number. Some software (e.g. my BIOS and vanilla Linux) plainly refuses to work with it, believing that it's not a keyboard.
2. It knows only scancode set 3. Typical PC keyboard uses set 2 and hence software usually expects set 2.
3. It needs to be explicitly told to send break codes, by default it sends them only for CTRL, ALT and SHIFT.
All of these issues can be easily solved in Linux - there is existing support for scancode set 3 and enabling break codes generation, and #1 requires only a very simple kernel patch. Now, if only my BIOS and USB adapters supported this keyboard, it would be perfect

If you would like to read more, there is a wiki article on attaching AT-compatible terminal Ms and Fs to PCs without USB adapters or controller swaps. IIRC, somebody has even developed a Windows driver for them.