[Libreboot] How to reinstall original Lenovo Bios and CPU Question

[chp]

Hi,

I am new to the list.

Thanks a lot to the maintainers for the excellent and usefull work!

I am working on some LCD testing for the T60.

For the moment, I have two questions:

1.)

I was able to flash libreboot with flashrom on a T60. For testing 
purposes I would like to flash the original Lenovo Bios. I have a backup 
file named "factory.bin" according to 
http://www.coreboot.org/Board:lenovo/x60/Installation#Back_up_the_original_proprietary_firmware

Is there any guide how to reinstall the original firmware? Is it right 
that I have to extract a .rom file from the factory.bin?

2.)

Why is the T5600 CPU recommended for the T60?

http://www.libreboot.org/docs/git/#build

"On a ThinkPad T60, you can replace the CPU (Core 2 Duo T5600, T7200 or 
T7600. T5600 recommended) for 64-bit support."

Best Regards,

chp