Well, I finally did it. A working coreboot install on my x60s. (model 1702)
First I had to find out what chip I had inside my x60s, I opened it (not easy, I can tell you that) and eventually found it next to a large chip with lenovo marking on it and a small toshiba chip on the underside of the pcb. It had a large black plastic sheet over it which I pulled off.
The actual chip itself had a little sticker on it with the text "KS2" if I remember correctly. I dabbed a ear cleaning swab into rubbing alcohol. That applied onto the chip with a bit of scratching with a pin got the sticker off.
After a lot of looking with a magnifying glass (its so tiny!) I found that it was marked "MX25L1605D".
Then I had to grab the flashrom source and edit it accordingly. I actually had to edit ".name = "MX25L1605" instead of ".name = "MX25l1605D" because 605D falls under the 605 family, so 605D does not exist as a stand alone ruleset.
I changed probe to "probe_spi_res1" model_id to "0x14" (will be different if you have a different chip of course) write to "spi_chip_write_1"
So then I ran make and it turned out that I needed to install pciutils, pciutils-dev and zlib1g-dev. So I did and it worked after that.
Next up was making coreboot.rom. I just installed libncurses-dev, iasl and libc6-dev-i386 and cloned the coreboot git repo. Did make menuconfig, chose lenovo as the mobo maker, chose the x60, 2mb chip size (used default payload, seabios), saved settings and ran make.
For bucts I just downloaded it and ran make.
Now that I had everything I simply did as the wiki page said and surprisingly, everything worked.
Well, almost everything. I didn't add in the vga rom so I don't get graphics preboot (which is to be expected) and sometimes the mouse and keyboard works, sometimes it doesn't. Sometimes one works and the other doesn't, I'll have to see if there a pattern sometime but it seems to work more often than not which is good.
All in all, with lots of help from the coreboot and flashrom mailing lists + irc I managed to flash coreboot successfully. Thanks everybody who helped me along the way (you know who you are) and I hope this inspires others to flash coreboot too.