Which one are you looking for? And why flash an old bootloader???
Upgrade/downgrade of the BL is usually done through flashing the official firmware. You can do it in fastboot, but that's risky stuff... Why would you?
I'll say....I have ICS installed on my /system partition, and the 10.6.1.14.40 bootloader I recently installed fails to boot the ICS kernel that I usually use. (It does boot Ubuntu however)
I have nvflash keys, so I like to live dangerously.
that@ws ~/android/tf700/bootloaders $ ls blob.EBT*
blob.EBT.10.4.4.16 blob.EBT.10.4.4.23 blob.EBT.10.6.1.14.4-US blob.EBT.9.4.5.26
blob.EBT.10.4.4.18 blob.EBT.10.4.4.25-US blob.EBT.10.6.1.14.4-WW blob.EBT.9.4.5.30
blob.EBT.10.4.4.20 blob.EBT.10.6.1.14.10-WW blob.EBT.10.6.1.14.8-US
Now you do...
Code:that@ws ~/android/tf700/bootloaders $ ls blob.EBT* blob.EBT.10.4.4.16 blob.EBT.10.4.4.23 blob.EBT.10.6.1.14.4-US blob.EBT.9.4.5.26 blob.EBT.10.4.4.18 blob.EBT.10.4.4.25-US blob.EBT.10.6.1.14.4-WW blob.EBT.9.4.5.30 blob.EBT.10.4.4.20 blob.EBT.10.6.1.14.10-WW blob.EBT.10.6.1.14.8-US
@bsammon: which one do you want?